Effects of Achyrocline satureioides Inflorescence Extracts against Pathogenic Intestinal Bacteria: Chemical Characterization, In Vitro Tests, and In Vivo Evaluation.

PubMed

Moresco, Karla Suzana; Silveira, Alexandre Kleber; Zeidán-Chuliá, Fares; Correa, Ana Paula Folmer; Oliveria, Rafael R; Borges, Adriana Giongo; Grun, Lucas; Barbé-Tuana, Florencia; Zmozinski, Ariane; Brandelli, Adriano; Vale, Maria Goretti Rodrigues; Gelain, Daniel Pens; Bassani, Valquiria Linck; Moreira, José Cláudio Fonseca

2017-01-01

Three Achyrocline satureioides (AS) inflorescences extracts were characterized: (i) a freeze-dried extract prepared from the aqueous extractive solution and (ii) a freeze-dried and (iii) a spray-dried extract prepared from hydroethanol extractive solution (80% ethanol). The chemical profile, antioxidant potential, and antimicrobial activity against intestinal pathogenic bacteria of AS extracts were evaluated. In vitro antioxidant activity was determined by the total reactive antioxidant potential (TRAP) assay. In vivo analysis and characterization of intestinal microbiota were performed in male Wistar rats (saline versus treated animals with AS dried extracts) by high-throughput sequencing analysis: metabarcoding. Antimicrobial activity was tested in vitro by the disc diffusion tests. Moisture content of the extracts ranged from 10 to 15% and 5.7 to 17 mg kg -1 of fluorine. AS exhibited antioxidant activity, especially in its freeze-dried form which also exhibited a wide spectrum of antimicrobial activity against intestinal pathogenic bacteria greater than those observed by the antibiotic, amoxicillin, when tested against Bacillus cereus and Staphylococcus aureus . Antioxidant and antimicrobial activities of AS extracts seemed to be positively correlated with the present amount of flavonoids. These findings suggest a potential use of AS as a coadjuvant agent for treating bacterial-induced intestinal diseases with high rates of antibiotic resistance.

Antimicrobial and biological activity of leachate from light curable pulp capping materials.

PubMed

Arias-Moliz, Maria Teresa; Farrugia, Cher; Lung, Christie Y K; Wismayer, Pierre Schembri; Camilleri, Josette

2017-09-01

Characterization of a number of pulp capping materials and assessment of the leachate for elemental composition, antimicrobial activity and cell proliferation and expression. Three experimental light curable pulp-capping materials, Theracal and Biodentine were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. The elemental composition of the leachate formed after 24h was assessed by inductively coupled plasma (ICP). The antimicrobial activity of the leachate was determined by the minimum inhibitory concentration (MIC) against multispecies suspensions of Streptococcus mutans ATCC 25175, Streptococcus gordonii ATCC 33478 and Streptococcus sobrinus ATCC 33399. Cell proliferation and cell metabolic function over the material leachate was assessed by an indirect contact test using 3-(4,5 dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The hydration behavior of the test materials varied with Biodentine being the most reactive and releasing the highest amount of calcium ions in solution. All materials tested except the unfilled resin exhibited depletion of phosphate ions from the solution indicating interaction of the materials with the media. Regardless the different material characteristics, there was a similar antimicrobial activity and cellular activity. All the materials exhibited no antimicrobial activity and were initially cytotoxic with cell metabolic function improving after 3days. The development of light curable tricalcium silicate-based pulp capping materials is important to improve the bonding to the final resin restoration. Testing of both antimicrobial activity and biological behavior is critical for material development. The experimental light curable materials exhibited promising biological properties but require further development to enhance the antimicrobial characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis and characterization of silver nanoparticles using Caesalpinia pulcherrima flower extract and assessment of their in vitro antimicrobial, antioxidant, cytotoxic, and genotoxic activities.

PubMed

Moteriya, Pooja; Chanda, Sumitra

2017-12-01

Caesalpinia pulcherrima flower extract mediated synthesis of silver nanoparticles was attempted in the present work including optimization of some procedure parameters. Characterization of synthesized silver nanoparticles was done by various spectral analyses. The size of synthesized silver nanoparticles was 12 nm and they were spherical in shape. The green synthesized silver nanoparticles were further evaluated for antimicrobial, antioxidant, cytotoxic, and genotoxic activities; they showed good antimicrobial, antioxidant, and cytotoxic effects. Genotoxic study revealed non-toxic nature at lower concentration. Overall results suggest that the synthesized silver nanoparticles have pronounced applicability in pharmaceutical and biomedical field.

Characterization of active paper packaging incorporated with ginger pulp oleoresin

NASA Astrophysics Data System (ADS)

Wiastuti, T.; Khasanah, L. U.; Atmaka Kawiji, W.; Manuhara, G. J.; Utami, R.

2016-02-01

Utilization of ginger pulp waste from herbal medicine and instant drinks industry in Indonesia currently used for fertilizer and fuel, whereas the ginger pulp still contains high oleoresin. Active paper packaging were developed incorporated with ginger pulp oleoresin (0%, 2%, 4%, and 6% w/w). Physical (thickness, tensile strength, and folding endurance, moisture content), sensory characteristics and antimicrobial activity of the active paper were evaluated. Selected active paper then were chemically characterized (functional groups). The additional of ginger pulp oleoresin levels are reduced tensile strength, folding endurance and sensory characteristic (color, texture and overall) and increased antimicrobial activity. Due to physical, sensory characteristic and antimicrobial activity, active paper with 2% ginger pulp oleoresin incorporation was selected. Characteristics of selected paper were 9.93% of water content; 0.81 mm of thickness; 0.54 N / mm of tensile strength; 0.30 of folding endurance; 8.43 mm inhibits the growth of Pseudomonas fluorescence and 27.86 mm inhibits the growth of Aspergillus niger (antimicrobial activity) and neutral preference response for sensory properties. For chemical characteristic, selected paper had OH functional group of ginger in 3422.83 cm-1 of wave number and indicated contain red ginger active compounds.

Purification and characterization of ribosomal proteins L27 and L30 having antimicrobial activity produced by the Lactobacillus salivarius SGL 03.

PubMed

Pidutti, P; Federici, F; Brandi, J; Manna, L; Rizzi, E; Marini, U; Cecconi, D

2018-02-01

The aim of this study was to investigate the antimicrobial potential of proteins secreted by a new strain of Lactobacillus salivarius. The secretome of L. salivarius SGL 03 strain was analysed by gel-assisted fractionation and MS/MS to identify low-molecular-mass proteins. This strategy allowed us to identify 10 secreted proteins. Then, a combination of heterologous expression and agar well diffusion was used to characterize them as to their antimicrobial activity, mechanisms of action and stability. Our findings indicate that L27 and L30 proteins of the 50S ribosomal subunit have antimicrobial activity against Streptococcus pyogenes, Streptococcus uberis and Enterococcus faecium. In addition, both proteins are bactericidal against S. pyogenes and maintain their antimicrobial activity after different protease treatments, at acidic pH, after heat treatment, and if stored in a refrigerated ambient at least at 4°C. The overall results demonstrated that the L27 and L30 ribosomal proteins are of interest as new antimicrobial molecules to prevent the growth of S. pyogenes, S. uberis and E. faecium. Our results provide the first insight into the extra-ribosomal activity of L27 and L30 secreted proteins of L. salivarius. This study demonstrated the capacity of L. salivarius SGL 03 to produce antimicrobial molecules and suggested this strain as a promising probiotic candidate. © 2017 The Society for Applied Microbiology.

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

PubMed

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.

Characterization and antimicrobial activity of sweetpotato starch-based edible film containing origanum (Thymus capitatus) oil.

PubMed

Ehivet, Fabienne E; Min, Byungjin; Park, Mi-Kyung; Oh, Jun-Hyun

2011-01-01

The objectives of this research were to characterize the mechanical and barrier properties of sweetpotato starch (SPS)-based film (SPSF) and to investigate the antimicrobial activity of SPSF containing origanum oil (OG) against foodborne pathogenic bacteria. The SPSF was fabricated with the SPS extracted from commercial sweetpotato roots. Tensile strength (TS), percent elongation at break (E), and water vapor permeability (WVP) were determined to characterize the SPSF fabricated with selected SPS concentrations, plasticizers, and the concentrations of plasticizers. The agar diffusion assay was used to determine the antimicrobial activity of SPSF containing selective concentrations of OG against Salmonella Enteritidis, Escherichia coli O157:H7, and Listeria monocytogenes. The SPSF fabricated with 2.5% SPS exhibited the greatest TS (4.58 MPa). The TS, E, and WVP of SPSF plasticized with 40% sorbitol exhibited 7.96 MPa, 77.92%, 0.212 ng m/m(2) S Pa, respectively. Therefore, the SPSF fabricated with 2.5% SPS and 40% sorbitol was determined as the optimum film. The antimicrobial activity of the SPSF containing OG increased as the concentration of OG increased. And the SPSF containing OG exhibited greater inhibitory effects against the gram-negative bacteria such as S. Enteritidis and E. coli O157:H7 than the gram-positive L. monocytogenes. The greatest antimicrobial activity was observed against S. Enteritidis when the SPSF containing 2% OG was applied, and the maximum square of zone width was 18.43 mm(2).

Synthesis, lipophilicity and antimicrobial activity evaluation of some new thiazolyl-oxadiazolines

PubMed Central

STOICA, CRISTINA IOANA; IONUȚ, IOANA; PÎRNĂU, ADRIAN; POP, CARMEN; ROTAR, ANCUȚA; VLASE, LAURIAN; ONIGA, SMARANDA; ONIGA, OVIDIU

2015-01-01

Background and aims Synthesis of new potential antimicrobial agents and evaluation of their lipophilicity. Methods Ten new thiazolyl-oxadiazoline derivatives were synthesized and their structures were validated by 1H-NMR and mass spectrometry. The lipophilicity of the compounds was evaluated using the principal component analysis (PCA) method. The necessary data for applying this method were obtained by reverse-phase thin-layer chromatography (RP-TLC). The antimicrobial activities were tested in vitro against four bacterial strains and one fungal strain. Results The lipophilicity varied with the structure but could not be correlated with the antimicrobial activity, since this was modest. Conclusions We have synthesized ten new heterocyclic compounds. After their physical and chemical characterization, we determined their lipophilicity and screened their antimicrobial activity. PMID:26733751

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

PubMed Central

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

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

PubMed

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.

Green synthesis of silver nanoparticles combined to calcium glycerophosphate: antimicrobial and antibiofilm activities.

PubMed

Souza, José As; Barbosa, Debora B; Berretta, Andresa A; do Amaral, Jackeline G; Gorup, Luiz F; de Souza Neto, Francisco N; Fernandes, Renan A; Fernandes, Gabriela L; Camargo, Emerson R; Agostinho, Alessandra M; Delbem, Alberto Cb

2018-03-01

To synthesize, characterize and evaluate the antimicrobial and antibiofilm activities of novel nanocomposites containing silver nanoparticles (AgNPs) associated or not to β-calcium glycerophosphate. These nanocomposites were produced through a 'green' route using extracts of different parts of pomegranate. Antimicrobial and antibiofilm properties against Candida albicans and Streptococcus mutans were determined by the minimum bactericidal/fungicidal concentration and biofilm density after treatments. All extracts used were successful in producing AgNPs. Composites made with peel extracts showed the highest antimicrobial and antibiofilm activity against both microorganisms tested and performed similarly or even better than chlorhexidine. AgNPs associated or not to calcium glycerophosphate produced by a 'green' process may be a promising novel antimicrobial agent against oral microorganisms.

Antibacterial nanosilver coated orthodontic bands with potential implications in dentistry.

PubMed

Prabha, Rahul Damodaran; Kandasamy, Rajasigamani; Sivaraman, U Sajeev; Nandkumar, Maya A; Nair, Prabha D

2016-10-01

Fixed orthodontic treatment, an indispensable procedure in orthodontics, necessitates insertion of dental bands. Insertion of band material could also introduce a site of plaque retention. It was hypothesized that band materials with slow-release antimicrobial properties could help in sustained infection control, prevention of dental plaque formation and further associated health risks. Considering the known antimicrobial proprieties of silver, a coating of silver nanoparticle (SNP) onto the stainless steel bands was done and characterized for its beneficial properties in the prevention of plaque accumulation. Coatings of SNPs on conventional stainless steel dental bands were prepared using thermal evaporation technology. The coated dental bands were characterized for their physicochemical properties and evaluated for antimicrobial activity and biocompatibility. The physiochemical characterization of band material both coated and uncoated was carried out using scanning electron microscope, energy dispersive spectroscopy, atomic force microscopyand contact angle test. Biocompatibility tests for coated band material were carried using L929 mouse fibroblast cell culture and MTT [3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay. Antimicrobial activity of coated band material against Gram-positive bacteria was tested. A stable and uniform coating of SNPs was obtained. The coated band materials were biocompatible as well as possessed distinct antimicrobial activity. The SNP coated dental bands could be potential antimicrobial dental bands for future clinical use. Further studies need to be done to validate the efficiency of coated band materials in oral environments.

Production of the antimicrobial peptides Caseicin A and B by Bacillus isolates growing on sodium caseinate.

PubMed

Kent, R M; Guinane, C M; O'Connor, P M; Fitzgerald, G F; Hill, C; Stanton, C; Ross, R P

2012-08-01

The aim of this study was to identify Bacillus isolates capable of degrading sodium caseinate and subsequently to generate bioactive peptides with antimicrobial activity. Sodium caseinate (2.5% w/v) was inoculated separately with 16 Bacillus isolates and allowed to ferment overnight. Protein breakdown in the fermentates was analysed using gel permeation-HPLC (GP-HPLC) and screened for peptides (<3-kDa) with MALDI-TOF mass spectrometry. Caseicin A (IKHQGLPQE) and caseicin B (VLNENLLR), two previously characterized antimicrobial peptides, were identified in the fermentates of both Bacillus cereus and Bacillus thuringiensis isolates. The caseicin peptides were subsequently purified by RP-HPLC and antimicrobial assays indicated that the peptides maintained the previously identified inhibitory activity against the infant formula pathogen Cronobacter sakazakii. We report a new method using Bacillus sp. to generate two previously characterized antimicrobial peptides from casein. This study highlights the potential to exploit Bacillus sp. or the enzymes they produce for the generation of bioactive antimicrobial peptides from bovine casein. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

Antimicrobial activity of ProRoot MTA in contact with blood

PubMed Central

Farrugia, C.; Baca, P.; Camilleri, J.; Arias Moliz, M. T.

2017-01-01

Dental materials based on Portland cement, which is used in the construction industry have gained popularity for clinical use due to their hydraulic properties, the interaction with tooth tissue and their antimicrobial properties. The antimicrobial properties are optimal in vitro. However in clinical use contact with blood may affect the antimicrobial properties. This study aims to assess whether antimicrobial properties of the Portland cement-based dental cements such as mineral trioxide aggregate (MTA) are also affected by contact with blood present in clinical situations. ProRoot MTA, a Portland cement-based dental cement was characterized following contact with water, or heparinized blood after 1 day and 7 days aging. The antimicrobial activity under the mentioned conditions was assessed using 3 antimicrobial tests: agar diffusion test, direct contact test and intratubular infection test. MTA in contact with blood was severely discoloured, exhibited an additional phosphorus peak in elemental analysis, no calcium hydroxide peaks and no areas of bacterial inhibition growth in the agar diffusion test were demonstrated. ProRoot MTA showed limited antimicrobial activity, in both the direct contact test and intratubular infection test. When aged in water ProRoot MTA showed higher antimicrobial activity than when aged in blood. Antimicrobial activity reduced significantly after 7 days. Further assessment is required to investigate behaviour in clinical situations. PMID:28128328

Purification and Characterization of a Mucin Specific Mycelial Lectin from Aspergillus gorakhpurensis: Application for Mitogenic and Antimicrobial Activity

PubMed Central

Singh, Ram Sarup; Kaur, Hemant Preet; Singh, Jatinder

2014-01-01

Background Lectins are carbohydrate binding proteins or glycoproteins that bind reversibly to specific carbohydrates present on the apposing cells, which are responsible for their ability to agglutinate red blood cells, lymphocytes, fibroblasts, etc. Interest in lectins has been intensified due to their carbohydrate specificity as they can be valuable reagents for the investigation of cell surface sugars, purification and characterization of glycoproteins. The present study reports the purification, characterization and evaluation of mitogenic and antimicrobial potential of a mycelial lectin from Aspergillus gorakhpurensis. Methods Affinity chromatography on mucin-sepharose column was carried out for purification of Aspergillus gorakhpurensis lectin. The lectin was characterized for physico-chemical parameters. Mitogenic potential of the lectin was evaluated against splenocytes of Swiss albino mice by MTT assay. Antimicrobial activity of the purified lectin has also been evaluated by disc diffusion assay. Results Single-step affinity purification resulted in 18.6-fold purification of the mycelial lectin. The molecular mass of the lectin was found to be 70 kDa and it was composed of two subunits of 34.8 kDa as determined by gel filtration chromatography, SDS-PAGE and MALDI-TOF analysis. pH optima of the lectin was found to be 6.5–9.5, while optimum temperature for lectin activity was 20–30°C. Lectin was stable within a pH range of 7.0–10.5 and showed fair thermostability. EDTA did not affect lectin activity whereas it was found susceptible to the denaturants tested. MTT assay revealed strong mitogenic potential of A. gorakhpurensis lectin at a concentration upto 150 µg/mL. Antimicrobial activity assay showed its potent antibacterial activity against Bacillus cereus, Staphylococcous aureus and Escherichia coli and marginal antifungal activity against Saccharomyces cerevisiae. Conclusion This is the first report on the mitogenic and antimicrobial potential of Aspergillus gorakhpurensis lectin. The results will provide useful guidelines for further research in clinical applications of this lectin. PMID:25286160

Purification and characterization of a mucin specific mycelial lectin from Aspergillus gorakhpurensis: application for mitogenic and antimicrobial activity.

PubMed

Singh, Ram Sarup; Kaur, Hemant Preet; Singh, Jatinder

2014-01-01

Lectins are carbohydrate binding proteins or glycoproteins that bind reversibly to specific carbohydrates present on the apposing cells, which are responsible for their ability to agglutinate red blood cells, lymphocytes, fibroblasts, etc. Interest in lectins has been intensified due to their carbohydrate specificity as they can be valuable reagents for the investigation of cell surface sugars, purification and characterization of glycoproteins. The present study reports the purification, characterization and evaluation of mitogenic and antimicrobial potential of a mycelial lectin from Aspergillus gorakhpurensis. Affinity chromatography on mucin-sepharose column was carried out for purification of Aspergillus gorakhpurensis lectin. The lectin was characterized for physico-chemical parameters. Mitogenic potential of the lectin was evaluated against splenocytes of Swiss albino mice by MTT assay. Antimicrobial activity of the purified lectin has also been evaluated by disc diffusion assay. Single-step affinity purification resulted in 18.6-fold purification of the mycelial lectin. The molecular mass of the lectin was found to be 70 kDa and it was composed of two subunits of 34.8 kDa as determined by gel filtration chromatography, SDS-PAGE and MALDI-TOF analysis. pH optima of the lectin was found to be 6.5-9.5, while optimum temperature for lectin activity was 20-30 °C. Lectin was stable within a pH range of 7.0-10.5 and showed fair thermostability. EDTA did not affect lectin activity whereas it was found susceptible to the denaturants tested. MTT assay revealed strong mitogenic potential of A. gorakhpurensis lectin at a concentration upto 150 µg/mL. Antimicrobial activity assay showed its potent antibacterial activity against Bacillus cereus, Staphylococcous aureus and Escherichia coli and marginal antifungal activity against Saccharomyces cerevisiae. This is the first report on the mitogenic and antimicrobial potential of Aspergillus gorakhpurensis lectin. The results will provide useful guidelines for further research in clinical applications of this lectin.

Synthesis and anti-microbial activity of hydroxylammonium ionic liquids.

PubMed

Ismail Hossain, M; El-Harbawi, Mohanad; Noaman, Yousr Abdulhadi; Bustam, Mohd Azmi B; Alitheen, Noorjahan Banu Mohamed; Affandi, Nor Azrin; Hefter, Glenn; Yin, Chun-Yang

2011-06-01

Eight hydroxylammonium-based room temperature ionic liquids (ILs) have been synthesized by acid-base neutralization of ethanolamines with organic acids. The ILs were characterized by infrared and nuclear magnetic resonance spectroscopies and elemental analysis. Their anti-microbial activities were determined using the well-diffusion method. All eight ILs were toxic to Staphylococcus aureus, while 2-hydroxyethylammonium lactate and 2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium acetate showed high anti-microbial activity against a wide range of human pathogens. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Bacteriocin from Bacillus subtilis as a novel drug against diabetic foot ulcer bacterial pathogens

PubMed Central

Joseph, Baby; Dhas, Berlina; Hena, Vimalin; Raj, Justin

2013-01-01

Objective To isolate and identify Bacillus subtilis (B. subtilis) from soil and to characterize and partially purify the bacteriocin. To evaluate the antimicrobial activity against four diabetic foot ulcer bacterial pathogens. Methods Genotypic identification was done based on Bergey's manual of systemic bacteriology. Antimicrobial susceptibility test was done by Kirby-Bauer disc diffusion method. Colonies were identified by colony morphology and biochemical characterization and also compared with MTCC 121 strain. Further identification was done by 16S rRNA sequencing. Inhibitory activities of partially purified bacteriocin on all the DFU isolates were done by agar well diffusion method. The strain was identified to produce bacteriocin by stab overlay assay. Bacteriocin was extracted by organic solvent extraction using chloroform, further purified by HPLC and physical, and chemical characterization was performed. Results The four isolates showed high level of resistance to amoxyclav and sensitivity to ciprofloxacin. HPLC purification revealed that the extracts are bacteriocin. The phylogenetic tree analysis results showed that the isolate was 99% related to B. subtilis BSF01. The results reveled activity to all the four isolates and high level of activity was seen in case of Klebsiella sp. Conclusions Partially purified bacteriocin was found to have antimicrobial activity against the four diabetic foot ulcer bacterial pathogens, which can thus be applied as a better drug molecule on further studies. The strain B. subtilis are found to be safe for use and these antimicrobial peptides can be used as an antimicrobial in humans to treat DFU bacterial pathogens. PMID:24093784

Bacteriocin from Bacillus subtilis as a novel drug against diabetic foot ulcer bacterial pathogens.

PubMed

Joseph, Baby; Dhas, Berlina; Hena, Vimalin; Raj, Justin

2013-12-01

To isolate and identify Bacillus subtilis (B. subtilis) from soil and to characterize and partially purify the bacteriocin. To evaluate the antimicrobial activity against four diabetic foot ulcer bacterial pathogens. Genotypic identification was done based on Bergey's manual of systemic bacteriology. Antimicrobial susceptibility test was done by Kirby-Bauer disc diffusion method. Colonies were identified by colony morphology and biochemical characterization and also compared with MTCC 121 strain. Further identification was done by 16S rRNA sequencing. Inhibitory activities of partially purified bacteriocin on all the DFU isolates were done by agar well diffusion method. The strain was identified to produce bacteriocin by stab overlay assay. Bacteriocin was extracted by organic solvent extraction using chloroform, further purified by HPLC and physical, and chemical characterization was performed. The four isolates showed high level of resistance to amoxyclav and sensitivity to ciprofloxacin. HPLC purification revealed that the extracts are bacteriocin. The phylogenetic tree analysis results showed that the isolate was 99% related to B. subtilis BSF01. The results reveled activity to all the four isolates and high level of activity was seen in case of Klebsiella sp. Partially purified bacteriocin was found to have antimicrobial activity against the four diabetic foot ulcer bacterial pathogens, which can thus be applied as a better drug molecule on further studies. The strain B. subtilis are found to be safe for use and these antimicrobial peptides can be used as an antimicrobial in humans to treat DFU bacterial pathogens. Copyright © 2013 Asian Pacific Tropical Biomedical Magazine. Published by Elsevier B.V. All rights reserved.

Extracellular synthesis of gold bionanoparticles by Nocardiopsis sp. and evaluation of its antimicrobial, antioxidant and cytotoxic activities.

PubMed

Manivasagan, Panchanathan; Alam, Moch Syaiful; Kang, Kyong-Hwa; Kwak, Minseok; Kim, Se-Kwon

2015-06-01

Advancement of biological process for the synthesis of bionanoparticles is evolving into a key area of research in nanotechnology. The present study deals with the biosynthesis, characterization of gold bionanoparticles by Nocardiopsis sp. MBRC-48 and evaluation of their antimicrobial, antioxidant and cytotoxic activities. The gold bionanoparticles obtained were characterized by UV-visible spectroscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray analysis and transmission electron microscopy (TEM). The synthesized gold bionanoparticles were spherical in shape with an average of 11.57 ± 1.24 nm as determined by TEM and dynamic light scattering (DLS) particle size analyzer, respectively. The biosynthesized gold nanoparticles exhibited good antimicrobial activity against pathogenic microorganisms. It showed strong antioxidant activity as well as cytotoxicity against HeLa cervical cancer cell line. The present study demonstrated the potential use of the marine actinobacterial strain of Nocardiopsis sp. MBRC-48 as an important source for gold nanoparticles with improved biomedical applications including antimicrobial, antioxidant as well as cytotoxic agent.

Prospective Source of Antimicrobial Compounds From Pigment Produced by Bacteria associated with Brown Alga ( Phaeophyceae ) Isolated from Karimunjawa island, Indonesia

NASA Astrophysics Data System (ADS)

Lunggani, A. T.; Darmanto, Y. S.; Radjasa, O. K.; Sabdono, A.

2018-02-01

Brown algae or Phaeophyceae characterized by their natural pigments that differ from other important algal classes. Several publications proves that brown algae - associated bacteria have great potential in developing marine pharmaceutical industry since they are capable to synthesized numerous bioactive metabolite compounds. However the potency of marine pigmented microbes associated with brown alga to produce natural pigments and antimicrobials has been less studied. Marine pigmented bacteria associated with brown algae collected from Karimunjawa Island were successfully isolated and screened for antimicrobial activity. The aim of this research was evaluated of the antimicrobial activity of pigments extracted from culturable marine pigmented bacteria on some pathogenic bacteria and yeast. The results showed that all isolates had antimicrobial activity and could be prospectively developed as antimicrobial agent producing pigments. The 6 marine pigmented bacteria was identified to genus level as Pseudoalteromonas, Sphingomonas, Serratia, Paracoccus, Vibrio.

A Low-Cost, Hands-on Module to Characterize Antimicrobial Compounds Using an Interdisciplinary, Biophysical Approach

PubMed Central

Kaushik, Karishma S.; Kessel, Ashley; Ratnayeke, Nalin; Gordon, Vernita D.

2015-01-01

We have developed a hands-on experimental module that combines biology experiments with a physics-based analytical model in order to characterize antimicrobial compounds. To understand antibiotic resistance, participants perform a disc diffusion assay to test the antimicrobial activity of different compounds and then apply a diffusion-based analytical model to gain insights into the behavior of the active antimicrobial component. In our experience, this module was robust, reproducible, and cost-effective, suggesting that it could be implemented in diverse settings such as undergraduate research, STEM (science, technology, engineering, and math) camps, school programs, and laboratory training workshops. By providing valuable interdisciplinary research experience in science outreach and education initiatives, this module addresses the paucity of structured training or education programs that integrate diverse scientific fields. Its low-cost requirements make it especially suitable for use in resource-limited settings. PMID:25602254

Novel antimicrobial peptides isolated from the skin secretions of Hainan odorous frog, Odorrana hainanensis.

PubMed

Wang, Hui; Yu, Zhijun; Hu, Yuhong; Li, Fengjiao; Liu, Limeng; Zheng, Hongyuan; Meng, Hao; Yang, Shujie; Yang, Xiaolong; Liu, Jingze

2012-06-01

Long time geographical isolation of Hainan Island from the China continent has resulted in appearance of many novel frog species. As one of them, Hainan odorous frog, Odorrana hainanensis possesses some special antimicrobial peptides distinct from those found in other Odorrana. In this study, three antimicrobial peptides have been purified and characterized from the skin secretion of O. hainanensis. With the similarity to the temporin family, two peptides are characterized by amidated C-terminals, so they are named as temporin-HN1 (AILTTLANWARKFL-NH(2)) and temporin-HN2 (NILNTIINLAKKIL-NH(2)). The third antimicrobial peptide belongs to the brevinin-1 family which is widely distributed in Eurasian ranids, and thus, it is named as brevinin-1HN1 (FLPLIASLAANFVPKIFCKITKKC). Furthermore, after sequencing 68 clones, eight cDNAs encoding antimicrobial peptide precursors were cloned from the skin-derived cDNA library of O. hainanensis. These eight cDNAs can encode seven mature antimicrobial peptides including the above three, as well as brevinin-1V, brevinin-2HS2, odorranain-A6, and odorranain-B1. Twelve different species of microorganisms were chosen, including Gram-positive, Gram-negative and fungi, to test the antimicrobial activities of temporin-HN1, temporin-HN2, brevinin-1HN1, brevinin-1V, and brevinin-2HS2. The result shows that, in addition to their activities against Gram-positive bacteria, temporin-HN1 and temporin-HN2 also possess activities against some Gram-negative bacteria and fungi. However, the two antimicrobial peptides, brevinin-1HN1 and brevinin-1V of the brevinin-1 family have stronger antimicrobial activities than temporin-HN1 and temporin-HN2 of the temporin family. Brevinin-1HN1 possesses activity against Staphylococcus aureus (ATCC25923), Rhodococcus rhodochrous X15, and Slime mould 090223 at the concentration of 1.2 μM. Copyright © 2012 Elsevier Inc. All rights reserved.

A novel cysteine-rich antimicrobial peptide from the mucus of the snail of Achatina fulica.

PubMed

Zhong, Jian; Wang, Wenhong; Yang, Xiaomei; Yan, Xiuwen; Liu, Rui

2013-01-01

Antimicrobial peptides (AMPs) are important components of the innate immunity. Many antimicrobial peptides have been found from marine mollusks. Little information about AMPs of mollusks living on land is available. A novel cysteine-rich antimicrobial peptide (mytimacin-AF) belonging to the peptide family of mytimacins was purified and characterized from the mucus of the snail of Achatina fulica. Its cDNA was also cloned from the cDNA library. Mytimacin-AF is composed of 80 amino acid residues including 10 cysteines. Mytimacin-AF showed potent antimicrobial activity against Gram-negative and Gram-positive bacteria and the fungus Candida albicans. Among tested microorganisms, it exerted strongest antimicrobial activity against Staphylococcus aureus with a minimal peptide concentration (MIC) of 1.9 μg/ml. Mytimacin-AF had little hemolytic activity against human blood red cells. The current work confirmed the presence of mytimacin-like antimicrobial peptide in land-living mollusks. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

Characterization of a Bacillus subtilis surfactin synthetase knockout and antimicrobial activity analysis.

PubMed

Liu, Hongxia; Qu, Xiaoxu; Gao, Ling; Zhao, Shengming; Lu, Zhaoxin; Zhang, Chong; Bie, Xiaomei

2016-11-10

Gene knockout is an important approach to improve the production of antimicrobial compounds. B. subtilis PB2-LS10, derived from B. subtilis PB2-L by a surfactin synthetase (srf) genes knockout, exhibits stronger inhibitory action than its parental strain against all tested pathogenic bacteria and fungi. The antimicrobial extracts produced by B. subtilis PB2-L and B. subtilis PB2-LS10 respectively were characterized by the high-resolution LC-ESI-MS. To provide further insight into the distinct antimicrobial activities, we investigated the impact of the srf genes deletion on the growth and gene transcriptional profile of the strains. The mutant strain grew quickly and reached stationary phase 2h earlier than the wild-type. Prominent expression changes in the modified strain involved genes that were essential to metabolic pathways and processes. Genes related to amino acid transport, ATP-binding cassette (ABC) transporters and protein export were up-regulated in strain PB2-LS10. However, amino acid metabolism, carbohydrate metabolism and fatty acid metabolism were repressed. Because of its excellent antimicrobial activity, strain PB2-LS10 has potential for use in food preservation. Copyright © 2016 Elsevier B.V. All rights reserved.

Antimicrobial activity of cream incorporated with silver nanoparticles biosynthesized from Withania somnifera

PubMed Central

Marslin, Gregory; Selvakesavan, Rajendran K; Franklin, Gregory; Sarmento, Bruno; Dias, Alberto CP

2015-01-01

We report on the antimicrobial activity of a cream formulation of silver nanoparticles (AgNPs), biosynthesized using Withania somnifera extract. Aqueous extracts of leaves promoted efficient green synthesis of AgNPs compared to fruits and root extracts of W. somnifera. Biosynthesized AgNPs were characterized for their size and shape by physical-chemical techniques such as UV-visible spectroscopy, laser Doppler anemometry, transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, and X-ray energy dispersive spectroscopy. After confirming the antimicrobial potential of AgNPs, they were incorporated into a cream. Cream formulations of AgNPs and AgNO3 were prepared and compared for their antimicrobial activity against human pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Proteus vulgaris, Escherichia coli, and Candida albicans) and a plant pathogen (Agrobacterium tumefaciens). Our results show that AgNP creams possess significantly higher antimicrobial activity against the tested organisms. PMID:26445537

New milk protein-derived peptides with potential antimicrobial activity: an approach based on bioinformatic studies.

PubMed

Dziuba, Bartłomiej; Dziuba, Marta

2014-08-20

New peptides with potential antimicrobial activity, encrypted in milk protein sequences, were searched for with the use of bioinformatic tools. The major milk proteins were hydrolyzed in silico by 28 enzymes. The obtained peptides were characterized by the following parameters: molecular weight, isoelectric point, composition and number of amino acid residues, net charge at pH 7.0, aliphatic index, instability index, Boman index, and GRAVY index, and compared with those calculated for known 416 antimicrobial peptides including 59 antimicrobial peptides (AMPs) from milk proteins listed in the BIOPEP database. A simple analysis of physico-chemical properties and the values of biological activity indicators were insufficient to select potentially antimicrobial peptides released in silico from milk proteins by proteolytic enzymes. The final selection was made based on the results of multidimensional statistical analysis such as support vector machines (SVM), random forest (RF), artificial neural networks (ANN) and discriminant analysis (DA) available in the Collection of Anti-Microbial Peptides (CAMP database). Eleven new peptides with potential antimicrobial activity were selected from all peptides released during in silico proteolysis of milk proteins.

New Milk Protein-Derived Peptides with Potential Antimicrobial Activity: An Approach Based on Bioinformatic Studies

PubMed Central

Dziuba, Bartłomiej; Dziuba, Marta

2014-01-01

New peptides with potential antimicrobial activity, encrypted in milk protein sequences, were searched for with the use of bioinformatic tools. The major milk proteins were hydrolyzed in silico by 28 enzymes. The obtained peptides were characterized by the following parameters: molecular weight, isoelectric point, composition and number of amino acid residues, net charge at pH 7.0, aliphatic index, instability index, Boman index, and GRAVY index, and compared with those calculated for known 416 antimicrobial peptides including 59 antimicrobial peptides (AMPs) from milk proteins listed in the BIOPEP database. A simple analysis of physico-chemical properties and the values of biological activity indicators were insufficient to select potentially antimicrobial peptides released in silico from milk proteins by proteolytic enzymes. The final selection was made based on the results of multidimensional statistical analysis such as support vector machines (SVM), random forest (RF), artificial neural networks (ANN) and discriminant analysis (DA) available in the Collection of Anti-Microbial Peptides (CAMP database). Eleven new peptides with potential antimicrobial activity were selected from all peptides released during in silico proteolysis of milk proteins. PMID:25141106

Structural characterization of 1,8-naphthalimides and in vitro microbiological activity of their Cu(II) and Zn(II) complexes

NASA Astrophysics Data System (ADS)

Grabchev, Ivo; Yordanova, Stanislava; Bosch, Paula; Vasileva-Tonkova, Evgenia; Kukeva, Rositsa; Stoyanov, Stanimir; Stoyanova, Radostina

2017-02-01

Two new 1,8-naphthalimide derivatives (NI1 and NI2) have been synthesized and characterized. The photophysical properties of the new compounds have been investigated in organic solvents of different polarity. It has been shown that both compounds are solvent depended. Cu(II) and Zn(II) complexes of NI2 were obtained and characterized by IR-NMR, fluorescence and EPR spectroscopy. The influence of different metal cations on the fluorescence intensity has been investigated in acetonitrile solution. Antimicrobial composite PLA-metal complexes materials have been obtained for the first time. Microbiological activity of both metal complexes has been investigated in vitro against different Gram-positive and Gram-negative bacteria and two yeasts. The various antimicrobial activities and the minimum inhibitory concentrations (MICs) of both complexes have been determined. The microbiological activity of composite materials PLA-metal complexes in thin polymeric film has also been investigated. The results suggest that the new metal complexes could find application in designing new antimicrobial preparations to control the spread of infections.

Screening of novel actinobacteria and characterization of the potential isolates from mangrove sediment of south coastal India.

PubMed

Arumugam, T; Senthil Kumar, P; Kameshwar, R; Prapanchana, K

2017-06-01

The importance of the current research is to investigate the different types of samples from the various mangrove sediments; as source of actinobacteria from the mangrove wet soil. Potential isolate screening by antimicrobial activity and identified actinobacteria was characterized based on cultural morphology, physiological and biochemical characteristics. Three different types of media were used to isolate actinobacteria from various geographical region of mangrove soil sediment and the genotype locus was recognized by 16S rDNA. Totally 144 actinobacteria isolates were recovered from 10 samples using three media. The most active culture media in the isolation of actinobacteria were ISP2 and Glycerol Yeast Extract Agar. Among 144 isolates, 38 isolates (26.38%) exhibited antimicrobial activity. Out of 38 isolates, potentially active 2 cultures were further supported for morphological and biochemical characterization analysis. Most of the isolates were produced pharmaceutically important enzymes such as protease, amylase, lipase, cellulose and also revealed antimicrobial activity against tested microorganism. The enriched salt, pH and temperature tolerance of the actinobacteria isolates to discharge commercially valuable primary and secondary bioactive metabolites. The present results functionally characterize novel mangrove actinobacteria and their metabolites for commercial interest in pharmaceutical industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transition metal complexes of quinolino[3,2-b]benzodiazepine and quinolino[3,2-b]benzoxazepine: synthesis, characterization, and antimicrobial studies.

PubMed

Basavaraju, B; Naik, Halehatty S Bhojya; Prabhakara, Mustur C

2007-01-01

The synthesis and characterization of title complexes of the ligand Quinolino[3,2-b]benzodiazepine (QBD) and Quinolino[3,2-b]benzoxazepine (QBO) are reported. The complexes have been characterized by elemental analysis, molar conductance, magnetic studies, IR, H1 NMR, and UV-visible studies. They have the stoichiometry [ML2C12], where M=Co(II)/Ni(II), L=QBD/QBO, and [MLC12], where M=Zn(II)/Cd(II), L=QBD/QBO. The antibacterial and antifungal activity of the metal complexes has been investigated. The complexes were found to have higher antimicrobial activity than the parent ligand.

Exploring the Antimicrobial and Antitumor Potentials of Streptomyces sp. AGM12-1 Isolated from Egyptian Soil

PubMed Central

Ahmad, Maged S.; El-Gendy, Ahmed O.; Ahmed, Rasha R.; Hassan, Hossam M.; El-Kabbany, Hussein M.; Merdash, Ahmed G.

2017-01-01

The occurrence of extensive antibiotics resistant bacteria increased the demands for mining out new sources of antimicrobial agents. Actinomycetes, especially Streptomyces sp. have grasped considerable attention worldwide due to production of many useful bioactive metabolites. In the present study, a total of 52 actinomycetes were isolated from agricultural soil samples in Beni-Suef, Egypt. All isolates were characterized based on colony morphology, mycelium coloration, and pigment diffusion. They were screened for their capabilities to show antimicrobial activities against different indicator microorganisms, and only 20 isolates have shown significant antimicrobial activities against at least one of the tested indicator microorganisms. The isolate AGM12-1 was active against all tested microorganisms and showed a marked antitumor activity with IC50 3.3 and 1.1 μg/ml against HCT-116 and HepG-2 cell lines respectively. It was genotypically characterized as Streptomyces sp. with the presence of PKS Π biosynthetic gene cluster. Mannitol, ammonium sulfate, pH 7, 2% inoculum size and incubation for 11 days at 30°C were the optimum conditions that used to maximize the production and hence allowed purification of one active antimicrobial compound to homogeneity using high performance liquid chromatography with a molecular mass of m/z 488.05. Nuclear magnetic resonance structural elucidation showed that this compound was a diketopiperazine derivative. PMID:28348553

Expression, purification and characterization of the recombinant cysteine-rich antimicrobial peptide snakin-1 in Pichia pastoris.

PubMed

Kuddus, Md Ruhul; Rumi, Farhana; Tsutsumi, Motosuke; Takahashi, Rika; Yamano, Megumi; Kamiya, Masakatsu; Kikukawa, Takashi; Demura, Makoto; Aizawa, Tomoyasu

2016-06-01

Snakin-1 (SN-1) is a small cysteine-rich plant antimicrobial peptide with broad spectrum antimicrobial activity which was isolated from potato (Solanum tuberosum). Here, we carried out the expression of a recombinant SN-1 in the methylotrophic yeast Pichia pastoris, along with its purification and characterization. A DNA fragment encoding the mature SN-1 was cloned into pPIC9 vector and introduced into P. pastoris. A large amount of pure recombinant SN-1 (approximately 40 mg/1L culture) was obtained from a fed-batch fermentation culture after purification with a cation exchange column followed by RP-HPLC. The identity of the recombinant SN-1 was verified by MALDI-TOF MS, CD and (1)H NMR experiments. All these data strongly indicated that the recombinant SN-1 peptide had a folding with six disulfide bonds that was identical to the native SN-1. Our findings showed that SN-1 exhibited strong antimicrobial activity against test microorganisms and produced very weak hemolysis of mammalian erythrocytes. The mechanism of its antimicrobial action against Escherichia coli was investigated by both outer membrane permeability assay and cytoplasmic membrane depolarization assay. These assays demonstrated that SN-1 is a membrane-active antimicrobial peptide which can disrupt both outer and cytoplasmic membrane integrity. This is the first report on the recombinant expression and purification of a fully active SN-1 in P. pastoris. Copyright © 2016 Elsevier Inc. All rights reserved.

From Synthesis to Biological Impact of Pd (II) Complexes: Synthesis, Characterization, and Antimicrobial and Scavenging Activity

PubMed Central

Sharma, Nitin Kumar; Ameta, Rakesh Kumar; Singh, Man

2016-01-01

The Pd (II) complexes with a series of halosubstituted benzylamine ligands (BLs) have been synthesized and characterized with different spectroscopic technique such as FTIR, UV/Vis, LCMS, 1H, and 13C NMR. Their molecular sustainability in different solvents such as DMSO, DMSO : H2O, and DMSO : PBS at physiological condition (pH 7.2) was determined by UV/Vis spectrophotometer. The in vitro antibacterial and antifungal activities of the complexes were investigated against Gram-positive and Gram-negative microbes and two different fungi indicated their significant biological potential. Additionally, their antioxidant activity has been analyzed with DPPH• free radical through spectrophotometric method and the result inferred them as an antioxidant. The stronger antibacterial and antioxidant activities of the synthesized complexes suggested them as a stronger antimicrobial agent. Our study advances the biological importance of palladium (II) amine complexes in the field of antimicrobial and antioxidant activities. PMID:27119023

GC/MS analysis and characterization of 2-Hexadecen-1-ol and beta sitosterol from Schimpera arabica extract for its bioactive potential as antioxidant and antimicrobial.

PubMed

Hidayathulla, S; Shahat, A A; Ahamad, S R; Al Moqbil, A A N; Alsaid, M S; Divakar, D D

2018-05-01

We evaluated the in vitro antioxidant and antimicrobial potential of Schimpera arabica extract and fractions (2-Hexadecen-1-ol and beta sitosterol). Free radical scavenging activity was estimated by using ABTS and DPPH methods, reducing power and iron chelation was studied to investigate antioxidant potential of the extracts. Well-diffusion method was utilized to evaluate the antimicrobial activity of the extracts. Gas chromatography-mass spectroscopy analysis of the extract revealed the presence of 27 compounds. Phenolic and flavonoid contents were found in high amount (7·6-18 mg GAE, mg g -1 ; 3·2-10·8 mg catechin, mg g -1 ) in dry plant material. Among all the extracts, 2-Hexadecen-1-ol and beta sitosterol were the major constituents of crude extract and exhibited significant antioxidant potential as well antimicrobial activity; however, all other fractions also exhibited fare degree of antioxidant potential. 93% DPPH was scavenged by 100 μg ml -1 of the ethyl acetate fraction; in ABTS assay chelation was 86·2 and 88% in ferric chloride reducing power assay. Schimpera arabica is naturally present and used in food preparation in most Arabian nations. The characterization of S. arabica would provide an insight into its medicinal use as home remedial for bacterial infection and as antioxidant. Significant and comparable antimicrobial activity was demonstrated by both 2-Hexadecen-1-ol and beta sitosterol fractions. The results suggest that S. arabica contain a good amount of natural antioxidants of medicinal importance. However, further investigations are needed to characterize the further activity of 2-Hexadecen-1-ol and beta sitosterol in vivo. © 2018 The Society for Applied Microbiology.

Facile fabrication and characterization of chitosan-based zinc oxide nanoparticles and evaluation of their antimicrobial and antibiofilm activity

NASA Astrophysics Data System (ADS)

Dhillon, Gurpreet Singh; Kaur, Surinder; Brar, Satinder Kaur

2014-06-01

The present investigation deals with the facile synthesis and characterization of chitosan (CTS)-based zinc oxide (ZnO) nanoparticles (NPs) and their antimicrobial activities against pathogenic microorganisms. ZnO-CTS NPs were synthesized through two different methods: nano spray drying and precipitation, using various organic compounds (citric acid, glycerol, starch and whey powder) as stabilizers. Both the synthesis methods were simple and were devoid of any chemical usage. The detailed characterization of the NPs was carried out using UV-Vis spectroscopy, dynamic light scattering particle size analysis, zeta potential measurements and scanning electron microscopy, which confirmed the fabrication of NPs with different shapes and sizes. Antimicrobial assay of synthesized ZnO-CTS NPs was carried out against different pathogenic microbial strains ( Candida albicans, Micrococcus luteus and Staphylococcus aureus). The significant ( p < 0.05) inhibition of growth was observed for both M. luteus and S. aureus with ZnO-CTS NPs (with a concentration ranging from 0.625 to 0.156 mg/ml) as compared to control treatment. ZnO-CTS NPs also showed significant biofilm inhibition activity ( p < 0.05) against M. luteus and S. aureus. The study demonstrated the potential of ZnO-CTS NPs as antimicrobial and antibiofilm agents.

Antagonistic interactions and production of halocin antimicrobial peptides among extremely halophilic prokaryotes isolated from the solar saltern of Sfax, Tunisia.

PubMed

Ghanmi, Fadoua; Carré-Mlouka, Alyssa; Vandervennet, Manon; Boujelben, Ines; Frikha, Doniez; Ayadi, Habib; Peduzzi, Jean; Rebuffat, Sylvie; Maalej, Sami

2016-05-01

Thirty-five extremely halophilic microbial strains isolated from crystallizer (TS18) and non-crystallizer (M1) ponds in the Sfax solar saltern in Tunisia were examined for their ability to exert antimicrobial activity. Antagonistic assays resulted in the selection of eleven strains that displayed such antimicrobial activity and they were further characterized. Three cases of cross-domain inhibition (archaea/bacteria or bacteria/archaea) were observed. Four archaeal strains exerted antimicrobial activity against several other strains. Three strains, for which several lines of evidence suggested the antimicrobial activity was, at least in part, due to peptide/protein agents (Halobacterium salinarum ETD5, Hbt. salinarum ETD8, and Haloterrigena thermotolerans SS1R12), were studied further. Optimal culture conditions for growth and antimicrobial production were determined. Using DNA amplification with specific primers, sequencing and RT-PCR analysis, Hbt. salinarum ETD5 and Hbt. salinarum ETD8 were shown to encode and express halocin S8, a hydrophobic antimicrobial peptide targeting halophilic archaea. Although the gene encoding halocin H4 was amplified from the genome of Htg. thermotolerans SS1R12, no transcript could be detected and the antimicrobial activity was most likely due to multiple antimicrobial compounds. This is also the first report that points to four different strains isolated from different geographical locations with the capacity to produce identical halocin S8 proteins.

Purification and characterization of two new cell-bound bioactive compounds produced by wild Lactococcus lactis strain.

PubMed

Saraiva, Margarete Alice Fontes; Brede, Dag Anders; Nes, Ingolf Figved; Baracat-Pereira, Maria Cristina; de Queiroz, Marisa Vieira; de Moraes, Célia Alencar

2017-07-03

Novel compounds and innovative methods are required considering that antibiotic resistance has reached a crisis point. In the study, two cell-bound antimicrobial compounds produced by Lactococcus lactis ID1.5 were isolated and partially characterized. Following purification by cationic exchange and a solid-phase C18 column, antimicrobial activity was recovered after three runs of RPC using 60% (v/v) and 100% (v/v) of 2-propanol for elution, suggesting that more than one antimicrobial compound were produced by L. lactis ID1.5, which were in this study called compounds AI and AII. The mass spectrum of AI and AII showed major intensity ions at m/z 1070.05 and 955.9 Da, respectively. The compound AI showed a spectrum of antimicrobial activity mainly against L. lactis species, while the organisms most sensitive to compound AII were Bacillus subtilis, Listeria innocua, Streptococcus pneumoniae and Pseudomonas aeruginosa. The antimicrobial activity of both compounds was suppressed by treatment with Tween 80. Nevertheless, both compounds showed high stability to heat and proteases treatments. The isolated compounds, AI and AII, showed distinct properties from other antimicrobial substances already reported as produced by L. lactis, and have a significant inhibitory effect against two clinically important respiratory pathogens. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Purification and characterization of antimicrobial peptides from fish isolate Carnobacterium maltaromaticum C2: Carnobacteriocin X and carnolysins A1 and A2.

PubMed

Tulini, Fabricio L; Lohans, Christopher T; Bordon, Karla C F; Zheng, Jing; Arantes, Eliane C; Vederas, John C; De Martinis, Elaine C P

2014-03-03

Carnobacterium maltaromaticum C2, isolated from Brazilian smoked fish (Surubim, Pseudoplatystoma sp.), was found to exert antimicrobial activity against Listeria monocytogenes, an important foodborne pathogen. In this study, the bacteriocins produced by C. maltaromaticum C2 were purified via an extraction with XAD-16 resin, a C18 solid phase extraction, followed by reversed-phase fast protein liquid chromatography. The purified active fractions were characterized using tandem mass spectrometry, permitting the identification of multiple bacteriocins. Carnobacteriocins BM1, B1, and a variant of carnobacteriocin B2 were all found, providing much of the antilisterial activity. Additionally, we herein report the first isolation of the previously predicted antimicrobial peptide carnobacteriocin X. Moreover, C. maltaromaticum C2 produces a novel two-component lantibiotic, termed carnolysin, homologous to enterococcal cytolysin. This lantibiotic is antimicrobially inactive when tested against the non-bacteriocinogenic strain C. maltaromaticum A9b-, likely requiring an additional proteolytic cleavage to reach maturity. Copyright © 2013 Elsevier B.V. All rights reserved.

Chemical and biological characterization of novel essential oils from Eremophila bignoniiflora (F. Muell) (Myoporaceae): a traditional Aboriginal Australian bush medicine.

PubMed

Sadgrove, Nicholas John; Hitchcock, Maria; Watson, Kenneth; Jones, Graham Lloyd

2013-10-01

Essential oils were extracted by hydrodistillation from the traditional Australian medicinal plant Eremophila bignoniiflora, characterized chemically and then screened for bioactivity. Characterization and quantification were completed using gas chromatography-mass spectrometry (GC-MS) and GC-flame ionization detection, respectively. Antimicrobial capacity was assessed using disc diffusion and micro-titre plate broth dilution and further characterized using thin layer chromatography followed by bioautography to assign activity to separated individual active components. Antifungal capacity was investigated using micro-titre plate broth dilution against pathogenic Trichophyton species. Free radical scavenging ability was assessed using the diphenylpicrylhydradyl reaction in methanol. The predominant components of the essential oil were fenchyl-acetate and bornyl-acetate. However, bioautography indicated antimicrobial ability to be largely linked to the less abundant, more polar constituents. Oils displayed only modest antifungal ability against pathogenic Trichophyton species associated with dermatophytosis, but moderate to high antimicrobial activity, particularly against the yeast Candida albicans and the bacteria Staphylococcus epidermidis. Essential oils exhibited relatively low free radical scavenging ability. Speculation over the role of essential oils in the traditional medicinal applications of E. bignoniiflora follows, exploring correlations between traditional use and investigated bioactivities. Copyright © 2012 John Wiley & Sons, Ltd.

Preparation and characterization of intelligent starch/PVA films for simultaneous colorimetric indication and antimicrobial activity for food packaging applications.

PubMed

Liu, Bin; Xu, Han; Zhao, Huiying; Liu, Wei; Zhao, Liyun; Li, Yuan

2017-02-10

We have developed an intelligent starch/poly-vinyl alcohol (PVA) film that is capable of monitoring pH changes and inhibiting undesired microbial growth in foods. Starch and PVA polymers in the film were doubly cross-linked by sodium trimetaphosphate and boric acid to improve their water-resistance and mechanical strength. Anthocyanins (ANT) and limonene (LIM) were used to achieve simultaneous colorimetric indication and antimicrobial activity. Firstly, the characterization of surface morphology using SEM confirmed that the starch-PVA-ANT-LIM film possessed a smooth surface. Secondly, the results of the mechanical strength test showed that starch-PVA-ANT-LIM possesses the highest mechanical strength. Additionally, there was a distinguishable change of colors as the film was immersed in solutions of pH ranging from 1.0 to 14.0. Moreover, the film showed excellent antimicrobial activity for three typical undesired microorganisms in foods, Bacillus subtilis, Aspergillus niger, and Staphylococcus aureus. Finally, the film exhibited good color indication and antimicrobial activity on pasteurized milk. The results suggest that the intelligent film reported here shows good capability for both alerting and inhibiting food spoilage. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ag/CuO nanoparticles prepared from a novel trinuclear compound [Cu(Imdz)4(Ag(CN)2)2] (Imdz = imidazole) by a pyrolysis display excellent antimicrobial activity

NASA Astrophysics Data System (ADS)

Adhikary, Jaydeep; Das, Balaram; Chatterjee, Sourav; Dash, Sandeep Kumar; Chattopadhyay, Sourav; Roy, Somenath; Chen, Jeng-Wei; Chattopadhyay, Tanmay

2016-06-01

One copper and two silver containing one hetero tri-nuclear precursor compound [Cu(Imdz)4(Ag(CN)2)2] (1) (Imdz = Imidazole) has been synthesized and characterized by single crystal X-ray diffraction. Simple pyrolysis of the complex at 550 °C for 4 h afforded Ag/CuO nanoparticles (NPs). The synthesized nanoparticles were characterized by ultraviolet-visible (UV-Vis), Fourier transform infrared (FT-IR), X-ray powder diffraction (XRPD), dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and X-ray photo electron spectroscopy (XPS). Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) have been employed as model microbial species to study the anti-microbial activity of the synthesized NPs. The NPs showed potent anti-microbial activity evidenced from the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values. Very high level of cell uptake and then generation of reactive oxygen species (ROS) are the origin of such strong antimicrobial activity for the NPs. However, the cytotoxicity level of the NPs towards normal human cell is very low.

Isolation and partial characterization of cyclic lipopeptide antibiotics produced by Paenibacillus ehimensis B7.

PubMed

Huang, Zhaohui; Hu, Yu; Shou, Linfei; Song, Mingxu

2013-04-17

The prevalence of drug-resistant bacteria has encouraged the search for novel antimicrobial compounds. Food-associated microorganisms, as a source of new antibiotics, have recently received considerable attention. The objective of this study was to find novel antimicrobial agents produced by food microorganisms. A bacterial strain B7, which has potent antimicrobial activity, was isolated from a sample of dairy waste. This strain was identified as Paenibacillus ehimensis based on the 16S rRNA gene sequence analysis, physiological and biochemical characterization. Two active compounds (PE1 and PE2) were obtained from P. ehimensis B7. Mass spectrometry (MS) analysis showed that the molecular masses of PE1 and PE2 were 1,114 and 1,100 Da, respectively. The tandem MS and amino acid analysis indicated that PE1 and PE2 were analogs of polypeptin, and PE2 was characterized as a new member of this family. Both compounds were active against all tested bacterial pathogens, including methicillin resistant Staphylococcus aureus, Escherichia coli, and pan-drug resistant Pseudomonas aeruginosa clinical isolate. Time-kill assays demonstrated that at 4 × MIC (minimum inhibitory concentration), PE1 and PE2 rapidly reduced the number of viable cells by at least 3-orders of magnitude, indicating that they were bactericidal antibiotics. In the present work, two cationic lipopeptide antibiotics (PE1 and PE2) were isolated from P. ehimensis B7 and characterized. These two peptides showed broad antimicrobial activity against all tested human pathogens and are worthy of further study.

Isolation and partial characterization of cyclic lipopeptide antibiotics produced by Paenibacillus ehimensis B7

PubMed Central

2013-01-01

Background The prevalence of drug-resistant bacteria has encouraged the search for novel antimicrobial compounds. Food-associated microorganisms, as a source of new antibiotics, have recently received considerable attention. The objective of this study was to find novel antimicrobial agents produced by food microorganisms. Results A bacterial strain B7, which has potent antimicrobial activity, was isolated from a sample of dairy waste. This strain was identified as Paenibacillus ehimensis based on the 16S rRNA gene sequence analysis, physiological and biochemical characterization. Two active compounds (PE1 and PE2) were obtained from P. ehimensis B7. Mass spectrometry (MS) analysis showed that the molecular masses of PE1 and PE2 were 1,114 and 1,100 Da, respectively. The tandem MS and amino acid analysis indicated that PE1 and PE2 were analogs of polypeptin, and PE2 was characterized as a new member of this family. Both compounds were active against all tested bacterial pathogens, including methicillin resistant Staphylococcus aureus, Escherichia coli, and pan-drug resistant Pseudomonas aeruginosa clinical isolate. Time-kill assays demonstrated that at 4 × MIC (minimum inhibitory concentration), PE1 and PE2 rapidly reduced the number of viable cells by at least 3-orders of magnitude, indicating that they were bactericidal antibiotics. Conclusions In the present work, two cationic lipopeptide antibiotics (PE1 and PE2) were isolated from P. ehimensis B7 and characterized. These two peptides showed broad antimicrobial activity against all tested human pathogens and are worthy of further study. PMID:23594351

Development of antimicrobial films for microbiological control of packaged salad.

PubMed

Muriel-Galet, Virginia; Cerisuelo, Josep P; López-Carballo, Gracia; Lara, Marta; Gavara, Rafael; Hernández-Muñoz, Pilar

2012-07-02

The aim of the present work was to characterize the antimicrobial efficiency of films consisting of PP/EVOH structures with oregano essential oil and citral. Both substances are known for their antimicrobial activity based on their interaction with the cell membrane. The films developed were used to pack minimally processed salads, combining modified atmosphere technology to extend shelf-life and active packaging technology to reduce possible microbiological risks. The antimicrobial activity of the films against the pathogenic microorganisms Escherichia coli, Salmonella enterica and Listeria monocytogenes and natural microflora was investigated "in vitro" and also on the food itself. The effect of release of the antimicrobial agent on the sensory characteristics of the salad was also studied. The results showed that antimicrobial activity reduced spoilage flora on the salad as well as inhibited the growth of pathogens in contaminated salads. This effect was greater against Gram-negative bacteria. Sensory studies showed that the package that was most effective and most accepted by customers was the one containing 5% oregano essential oil. Copyright © 2012 Elsevier B.V. All rights reserved.

Bioprospecting saline gradient of a Wildlife Sanctuary for bacterial diversity and antimicrobial activities.

PubMed

DeLuca, Mara; King, Riley; Morsy, Mustafa

2017-08-11

Antibiotic-resistant bacteria are becoming a global crisis, causing death of thousands of people and significant economic impact. The discovery of novel antibiotics is crucial to saving lives and reducing healthcare costs. To address the antibiotic-resistant crisis, in collaboration the Small World Initiative, which aims to crowdsource novel antibiotic discovery, this study aimed to identify antimicrobial producing bacteria and bacterial diversity in the soil of the Stimpson Wildlife Sanctuary, an inland area with a soil salt gradient. Approximately 4500 bacterial colonies were screened for antimicrobial activity and roughly 100 bacteria were identified as antimicrobial producers, which belong to Entrococcaceae (74%), Yersiniaceae (19%), and unidentified families (7%). Several bacterial isolates showed production of broad spectrum inhibitory compounds, while others were more specific to certain pathogens. The data obtained from the current study provide a resource for further characterization of the soil bacteria with antimicrobial activity, with an aim to discover novel ones. The study showed no correlation between soil salt level and the presence of bacteria with antimicrobial activities. However, most of the identified antimicrobial producing bacteria do not belong to actinomycetes, the most common phyla of antibiotic producing bacteria and this could potentially lead to the discovery of novel antibiotics.

Transition Metal Complexes of Quinolino[3,2-b]benzodiazepine and Quinolino[3,2-b]benzoxazepine: Synthesis, Characterization, and Antimicrobial Studies

PubMed Central

Basavaraju, B.; Bhojya Naik, Halehatty S.; Prabhakara, Mustur C.

2007-01-01

The synthesis and characterization of title complexes of the ligand Quinolino[3,2-b]benzodiazepine (QBD) and Quinolino[3,2-b]benzoxazepine (QBO) are reported. The complexes have been characterized by elemental analysis, molar conductance, magnetic studies, IR, H1 NMR, and UV-visible studies. They have the stoichiometry [ML2C12], where M=Co(II)/Ni(II), L=QBD/QBO, and [MLC12], where M=Zn(II)/Cd(II), L=QBD/QBO. The antibacterial and antifungal activity of the metal complexes has been investigated. The complexes were found to have higher antimicrobial activity than the parent ligand. PMID:18273383

Characterization of Antimicrobial Poly (Lactic Acid)/Nano-Composite Films with Silver and Zinc Oxide Nanoparticles

PubMed Central

Chu, Zhuangzhuang; Zhao, Tianrui; Li, Lin; Fan, Jian; Qin, Yuyue

2017-01-01

Antimicrobial active films based on poly (lactic acid) (PLA) were prepared with nano-silver (nano-Ag) and nano-zinc oxide (nano-ZnO) using a solvent volatilizing method. The films were characterized for mechanical, structural, thermal, physical and antimicrobial properties. Scanning electron microscopy (SEM) images characterized the fracture morphology of the films with different contents of nano-Ag and nano-ZnO. The addition of nanoparticles into the pure PLA film decreased the tensile strength and elasticity modulus and increased the elongation of breaks—in other words, the flexibility and extensibility of these composites improved. According to the results of differential scanning calorimetry (DSC), the glass transition temperature of the PLA nano-composite films decreased, and the crystallinity of these films increased; a similar result was apparent from X-ray diffraction (XRD) analysis. The water vapor permeability (WVP) and opacity of the PLA nano-composite films augmented compared with pure PLA film. Incorporation of nanoparticles to the PLA films significantly improved the antimicrobial activity to inhibit the growth of Escherichia coli. The results indicated that PLA films with nanoparticles could be considered a potential environmental-friendly packaging material. PMID:28773018

Deep Subseafloor Fungi as an Untapped Reservoir of Amphipathic Antimicrobial Compounds.

PubMed

Navarri, Marion; Jégou, Camille; Meslet-Cladière, Laurence; Brillet, Benjamin; Barbier, Georges; Burgaud, Gaëtan; Fleury, Yannick

2016-03-10

The evolving global threat of antimicrobial resistance requires a deep renewal of the antibiotic arsenal including the isolation and characterization of new drugs. Underexplored marine ecosystems may represent an untapped reservoir of novel bioactive molecules. Deep-sea fungi isolated from a record-depth sediment core of almost 2000 m below the seafloor were investigated for antimicrobial activities. This antimicrobial screening, using 16 microbial targets, revealed 33% of filamentous fungi synthesizing bioactive compounds with activities against pathogenic bacteria and fungi. Interestingly, occurrence of antimicrobial producing isolates was well correlated with the complexity of the habitat (in term of microbial richness), as higher antimicrobial activities were obtained at specific layers of the sediment core. It clearly highlights complex deep-sea habitats as chemical battlefields where synthesis of numerous bioactive compounds appears critical for microbial competition. The six most promising deep subseafloor fungal isolates were selected for the production and extraction of bioactive compounds. Depending on the fungal isolates, antimicrobial compounds were only biosynthesized in semi-liquid or solid-state conditions as no antimicrobial activities were ever detected using liquid fermentation. An exception was made for one fungal isolate, and the extraction procedure designed to extract amphipathic compounds was successful and highlighted the amphiphilic profile of the bioactive metabolites.

Potential antimicrobial agents from triazole-functionalized 2H-benzo[b][1,4]oxazin-3(4H)-ones.

PubMed

Bollu, Rajitha; Banu, Saleha; Bantu, Rajashaker; Reddy, A Gopi; Nagarapu, Lingaiah; Sirisha, K; Kumar, C Ganesh; Gunda, Shravan Kumar; Shaik, Kamal

2017-12-01

A series of substituted triazole functionalized 2H-benzo[b][1,4]oxazin-3(4H)-ones were synthesized by employing click chemistry and further characterized based on 1 H NMR, 13 C NMR, IR and mass spectral studies. All the synthesized derivatives were screened for their in vitro antimicrobial activities. Further, molecular docking studies were accomplished to explore the binding interactions between 1,2,3-triazol-4-yl-2H-benzo[b][1,4]oxazin-3(4H)-one and the active site of Staphylococcus aureus (CrtM) dehydrosqualene synthase (PDB ID: 2ZCS). These docking studies revealed that the synthesized derivatives showed high binding energies and strong H-bond interactions with the dehydrosqualene synthase validating the observed antimicrobial activity data. Based on antimicrobial activity and docking studies, the compounds 9c, 9d and 9e were identified as promising antimicrobial leads. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of Silver Nanoparticles with Strong and Stable Antimicrobial Activity against Highly Pathogenic and Multidrug Resistant Bacteria

PubMed Central

Saeb, Amr T. M.; Alshammari, Ahmad S.; Al-Brahim, Hessa; Al-Rubeaan, Khalid A.

2014-01-01

Aims. To synthesize, characterize, and analyze antimicrobial activity of AgNPs of Escherichia hermannii (SHE), Citrobacter sedlakii (S11P), and Pseudomonas putida (S5). Methods. The synthesized AgNPs were examined using ultraviolet-visible spectroscopy (UV-vis) and, zeta potential, and the size and the morphology obtained from the three different isolates were also confirmed by TEM. Results. Among the three isolates tested, SHE showed the best antimicrobial activity due to the presence of small (4–12 nm) and stable (−22 mV) AgNPs. Stability of AgNPs was also investigated and found to be dependent on the nature of isolates. Conclusion. Produced AgNPs showed particle stability and antimicrobial efficacy up to 90 days of production. Our AgNPs exhibited greater antimicrobial activity compared with gentamicin against P. aeruginosa isolates and vancomycin against S. aureus and MRSA isolates at very low concentration (0.0002 mg per Microliters). PMID:25093206

Antimicrobial activity and phytochemical characterization of Carya illinoensis.

PubMed

Bottari, Nathieli Bianchin; Lopes, Leonardo Quintana Soares; Pizzuti, Kauana; Filippi Dos Santos Alves, Camilla; Corrêa, Marcos Saldanha; Bolzan, Leandro Perger; Zago, Adriana; de Almeida Vaucher, Rodrigo; Boligon, Aline Augusti; Giongo, Janice Luehring; Baldissera, Matheus Dellaméa; Santos, Roberto Christ Vianna

2017-03-01

Carya illinoensis is a widespread species, belonging to the Juglandaceae family, commonly known as Pecan. Popularly, the leaves have been used in the treatment of smoking as a hypoglycemic, cleansing, astringent, keratolytic, antioxidant, and antimicrobial agent. The following research aimed to identify for the first time the phytochemical compounds present in the leaves of C. illinoensis and carry out the determination of antimicrobial activity of aqueous and ethanolic extracts. The antimicrobial activity was tested against 20 microorganisms by determining the minimum inhibitory concentration (MIC). Phenolic acids (gallic acid and ellagic acid), flavonoids (rutin), and tannins (catechins and epicatechins) were identified by HPLC-DAD and may be partially responsible for the antimicrobial activity against Gram-positive, Gram-negative, and yeast. The results showed MIC values between 25 mg/mL and 0.78 mg/mL. The extracts were also able to inhibit the production of germ tubes by Candida albicans. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis, characterization and anti-microbial evaluation of Cu(II), Ni(II), Pt(II) and Pd(II) sulfonylhydrazone complexes; 2D-QSAR analysis of Ni(II) complexes of sulfonylhydrazone derivatives

NASA Astrophysics Data System (ADS)

Özbek, Neslihan; Alyar, Saliha; Alyar, Hamit; Şahin, Ertan; Karacan, Nurcan

2013-05-01

Copper(II), nickel(II), platinum(II) and palladium(II) complexes with 2-hydroxy-1-naphthaldehyde-N-methylpropanesulfonylhydrazone (nafpsmh) derived from propanesulfonic acid-1-methylhydrazide (psmh) were synthesized, their structure were identified, and antimicrobial activity of the compounds was screened against three Gram-positive and three Gram-negative bacteria. The results of antimicrobial studies indicate that Pt(II) and Pd(II) complexes showed the most activity against all bacteria. The crystal structure of 2-hydroxy-1-naphthaldehyde-N-methylpropanesulfonylhydrazone (nafpsmh) was also investigated by X-ray analysis. A series of Ni(II) sulfonyl hydrazone complexes (1-33) was synthesized and tested in vitro against Escherichia coli and Staphylococcus aureus. Their antimicrobial activities were used in the QSAR analysis. Four-parameter QSAR models revealed that nucleophilic reaction index for Ni and O atoms, and HOMO-LUMO energy gap play key roles in the antimicrobial activity.

Isolation and characterization of large spectrum and multiple bacteriocin-producing Enterococcus faecium strain from raw bovine milk.

PubMed

Gaaloul, N; ben Braiek, O; Hani, K; Volski, A; Chikindas, M L; Ghrairi, T

2015-02-01

To assess the antimicrobial properties of lactic acid bacteria from Tunisian raw bovine milk. A bacteriocin-producing Enterococcus faecium strain was isolated from raw cow milk with activity against Gram-positive and Gram-negative bacteria. Antimicrobial substances produced by this strain were sensitive to proteolytic enzymes and were thermostable and resistant to a broad range of pH (2-10). Mode of action of antimicrobial substances was determined as bactericidal. Maximum activity was reached at the end of the exponential growth phase when checked against Listeria ivanovii BUG 496 (2366.62 AU ml(-1)). However, maximum antimicrobial activity against Pseudomonas aeruginosa 28753 was recorded at the beginning of the exponential growth phase. Enterococcus faecium GGN7 was characterized as free from virulence factors and was susceptible to tested antibiotics. PCR analysis of the micro-organism's genome revealed the presence of genes coding for enterocins A and B. Mass spectrometry analysis of RP-HPLC active fractions showed molecular masses corresponding to enterocins A (4835.77 Da) and B (5471.56 Da), and a peptide with a molecular mass of 3215.5 Da active only against Gram-negative indicator strains. The latter was unique in the databases. Enterococcus faecium GGN7 produces three bacteriocins with different inhibitory spectra. Based on its antimicrobial properties and safety, Ent. faecium GGN7 is potentially useful for food biopreservation. The results suggest the bacteriocins from GGN7 strain could be useful for food biopreservation. © 2014 The Society for Applied Microbiology.

Isolation, purification, and characterization of antimicrobial compound 6-[1,2-dimethyl-6-(2-methyl-allyloxy)-hexyl]-3-(2-methoxy-phenyl)-chromen-4-one from Penicillium sp. HT-28.

PubMed

Kaur, Harpreet; Arora, Daljit Singh; Sharma, Vishal

2014-08-01

A fungal culture (Penicillium sp., HT-28), isolated from soil has been evaluated for its bioactivity, which showed broad spectrum antimicrobial activity and was effective against methicillin-resistant Staphylococcus aureus (MRSA) also. Statistical optimization of the medium by response surface methodology (RSM) enhanced the antimicrobial activity up to 1.8-fold. Column chromatography was used to isolate the active compound (A), which was characterized to be 6-[1,2-dimethyl-6-(2-methyl-allyloxy)-hexyl]-3-(2-methoxy-phenyl)-chromen-4-one by various spectroscopic techniques such as infrared (IR), (1)H and (13)C nuclear magnetic resonance (NMR) spectra, and mass spectroscopy. Minimum inhibitory concentration (MIC) of the active compound (A) ranged from 0.5 to 15 μg/mL. Viable cell count studies of the active compound (A) showed S. aureus, Escherichia coli, Staphylococcus epidermidis, and Salmonella typhimurium 1 to be the most sensitive. The compound retained its bioactivity after treating it at 100 °C for 1 h. Furthermore, the compound (A) when tested for its biosafety was found neither to be cytotoxic nor mutagenic. The study demonstrated that an apparently novel compound isolated from Penicillium sp. (HT-28) seems to be a stable and potent antimicrobial.

Synthesis and Complete Antimicrobial Characterization of CEOBACTER, an Ag-Based Nanocomposite

PubMed Central

Vasquez-Peña, M.; Raymond-Herrera, O.; Villavicencio-García, H.; Petranovskii, V.; Vazquez-Duhalt, R.; Huerta-Saquero, A.

2016-01-01

The antimicrobial activity of silver nanoparticles (AgNPs) is currently used as an alternative disinfectant with diverse applications, ranging from decontamination of aquatic environments to disinfection of medical devices and instrumentation. However, incorporation of AgNPs to the environment causes collateral damage that should be avoided. In this work, a novel Ag-based nanocomposite (CEOBACTER) was successfully synthetized. It showed excellent antimicrobial properties without the spread of AgNPs into the environment. The complete CEOBACTER antimicrobial characterization protocol is presented herein. It is straightforward and reproducible and could be considered for the systematic characterization of antimicrobial nanomaterials. CEOBACTER showed minimal bactericidal concentration of 3 μg/ml, bactericidal action time of 2 hours and re-use capacity of at least five times against E. coli cultures. The bactericidal mechanism is the release of Ag ions. CEOBACTER displays potent bactericidal properties, long lifetime, high stability and re-use capacity, and it does not dissolve in the solution. These characteristics point to its potential use as a bactericidal agent for decontamination of aqueous environments. PMID:27824932

An endogenous ribonuclease inhibitor regulates the antimicrobial activity of ribonuclease 7 in the human urinary tract

PubMed Central

Spencer, John David; Schwaderer, Andrew L.; Eichler, Tad; Wang, Huanyu; Kline, Jennifer; Justice, Sheryl S.; Cohen, Daniel M.; Hains, David S.

2013-01-01

Recent studies stress the importance of antimicrobial peptides in protecting the urinary tract from infection. Previously, we have shown that ribonuclease 7 (RNase 7) is a potent antimicrobial peptide that has broad-spectrum antimicrobial activity against uropathogenic bacteria. The urothelium of the lower urinary tract and intercalated cells of the kidney produce RNase 7 but regulation of its antimicrobial activity has not been well defined. Here we characterize the expression of an endogenous inhibitor, ribonuclease inhibitor (RI), in the urinary tract and evaluate its effect on RNase 7’s antimicrobial activity. Using RNA isolated from non-infected human bladder and kidney tissue, quantitative real-time PCR showed that RNH1, the gene encoding RI, is constitutively expressed throughout the urinary tract. With pyelonephritis, RNH1 expression and RI peptide production significantly decrease. Immunostaining localized RI production to the umbrella cells of the bladder and intercalated cells of the renal collecting tubule. In vitro assays showed that RI bound to RNase 7 and suppressed its antimicrobial activity by blocking its ability to bind the cell wall of uropathogenic bacteria. Thus, these results demonstrate a new immunomodulatory role for RI and identified a unique regulatory pathway that may affect how RNase 7 maintains urinary tract sterility. PMID:24107847

Insights into the Antimicrobial Mechanism of Action of Human RNase6: Structural Determinants for Bacterial Cell Agglutination and Membrane Permeation

PubMed Central

Pulido, David; Arranz-Trullén, Javier; Prats-Ejarque, Guillem; Velázquez, Diego; Torrent, Marc; Moussaoui, Mohammed; Boix, Ester

2016-01-01

Human Ribonuclease 6 is a secreted protein belonging to the ribonuclease A (RNaseA) superfamily, a vertebrate specific family suggested to arise with an ancestral host defense role. Tissue distribution analysis revealed its expression in innate cell types, showing abundance in monocytes and neutrophils. Recent evidence of induction of the protein expression by bacterial infection suggested an antipathogen function in vivo. In our laboratory, the antimicrobial properties of the protein have been evaluated against Gram-negative and Gram-positive species and its mechanism of action was characterized using a membrane model. Interestingly, our results indicate that RNase6, as previously reported for RNase3, is able to specifically agglutinate Gram-negative bacteria as a main trait of its antimicrobial activity. Moreover, a side by side comparative analysis with the RN6(1–45) derived peptide highlights that the antimicrobial activity is mostly retained at the protein N-terminus. Further work by site directed mutagenesis and structural analysis has identified two residues involved in the protein antimicrobial action (Trp1 and Ile13) that are essential for the cell agglutination properties. This is the first structure-functional characterization of RNase6 antimicrobial properties, supporting its contribution to the infection focus clearance. PMID:27089320

Antimicrobial activity in the common seawhip, Leptogorgia virgulata (Cnidaria: Gorgonaceae).

PubMed

Shapo, Jacqueline L; Moeller, Peter D; Galloway, Sylvia B

2007-09-01

Antimicrobial activity was examined in the gorgonian Leptogorgia virgulata (common seawhip) from South Carolina waters. Extraction and assay protocols were developed to identify antimicrobial activity in crude extracts of L. virgulata. Detection was determined by liquid growth inhibition assays using Escherichia coli BL21, Vibrio harveyii, Micrococcus luteus, and a Bacillus sp. isolate. This represents the first report of antimicrobial activity in L. virgulata, a temperate/sub-tropical coral of the western Atlantic Ocean. Results from growth inhibition assays guided a fractionation scheme to identify active compounds. Reverse-phase HPLC, HPLC-mass spectrometry, and 1H and 13C NMR spectroscopy were used to isolate, purify, and characterize metabolites in antimicrobial fractions of L. virgulata. Corroborative HPLC-MS/NMR evidence validated the presence of homarine and a homarine analog, well-known emetic metabolites previously isolated from L. virgulata, in coral extracts. In subsequent assays, partially-purified L. virgulata fractions collected from HPLC-MS fractionation were shown to contain antimicrobial activity using M. luteus and V. harveyii. This study provides evidence that homarine is an active constituent of the innate immune system in L. virgulata. We speculate it may act synergistically with cofactors and/or congeners in this octocoral to mount a response to microbial invasion and disease.

Synthesis, characterization and biological studies of substituted quinozoline-4-(3H)-ones containing diazepine moiety.

PubMed

Narayana Rao, D V; Raghavendra Guru Prasad, A; Spoorthy, Y N; Pariplavi, M; Ravindranath, L K

2014-01-01

The synthesis and characterization of new series of 1,4-benzodiazepine derivatives have been presented. The structures were confirmed by elemental analyses, IR spectral, (1)H NMR spectral and mass spectral data. All the compounds were screened for in vitro antimicrobial and anthelmintic activities. The antibacterial activity was tested against Staphylococcus aureus (Gram positive), Bacillus cereus (Gram positive), Escherichia coli (Gram negative) and Pseudomonas aeruginosa (Gram negative). The antifungal activity was tested against Aspergillus niger and Candida albicans. All the compounds showed considerable antimicrobial activity against the microorganism studied. The significant anthelmintic activity of all novel compounds was demonstrated against Pheretima posthuma. Based on the nature of substituent present, the structure-activity correlation of novel compounds was discussed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Synthesis and structure-activity relationships of novel cationic lipids with anti-inflammatory and antimicrobial activities.

PubMed

Myint, Melissa; Bucki, Robert; Janmey, Paul A; Diamond, Scott L

2015-07-15

Certain membrane-active cationic steroids are known to also possess both anti-inflammatory and antimicrobial properties. This combined functionality is particularly relevant for potential therapies of infections associated with elevated tissue damage, for example, cystic fibrosis airway disease, a condition characterized by chronic bacterial infections and ongoing inflammation. In this study, six novel cationic glucocorticoids were synthesized using beclomethasone, budesonide, and flumethasone. Products were either monosubstituted or disubstituted, containing one or two steroidal groups, respectively. In vitro evaluation of biological activities demonstrated dual anti-inflammatory and antimicrobial properties with limited cytotoxicity for all synthesized compounds. Budesonide-derived compounds showed the highest degree of both glucocorticoid and antimicrobial properties within their respective mono- and disubstituted categories. Structure-activity analyses revealed that activity was generally related to the potency of the parent glucocorticoid. Taken together, these data indicate that these types of dual acting cationic lipids can be synthesized with the appropriate starting steroid to tailor activities as desired. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identification and Biochemical Characterization of Small-Molecule Inhibitors of Clostridium Botulinum Neurotoxin Serotype A

DTIC Science & Technology

2009-08-01

the BoNT/A protease activity were selected. Database search queries of the best candidate hit [7-((4-nitro- anilino)(phenyl) methyl )-8-quinolinol (NSC...therapeutic challenges. Trends Mol. Med. 9:291–299. 18. Gershon, H., and R. Parmegiani. 1963. Antimicrobial activity of 8-quinoli- nol, its salts with salicylic ...Parmegiani. 1962. Antimicrobial activity of 8-quinoli- nols, salicylic acids, hydroxynaphthoic acids, and salts of selected quinolinols with selected

Antimicrobial activity of blended essential oil preparation.

PubMed

Tadtong, Sarin; Suppawat, Supatcha; Tintawee, Anchalee; Saramas, Phanida; Jareonvong, Suchada; Hongratanaworakit, Tapanee

2012-10-01

Antimicrobial activities of two blended essential oil preparations comprising lavender oil, petigrain oil, clary sage oil, ylang ylang oil and jasmine oil were evaluated against various pathogenic microorganisms. Both preparations showed antimicrobial activity in the agar disc diffusion assay against the Gram-positive bacteria, Staphylococcus aureus ATCC6538 and S. epidermidis isolated strain, the fungus, Candida albicans ATCC10231, and the Gram-negative bacterium, Escherichia coli ATCC25922, but showed no activity against Pseudomonas aeruginosa ATCC9027. The minimum inhibitory concentration (MIC) of these preparations was evaluated. By the broth microdilution assay, preparation 1, comprising lavender oil, clary sage oil, and ylang ylang oil (volume ratio 3:4:3), exhibited stronger antimicrobial activity than preparation 2, which was composed of petigrain oil, clary sage oil, and jasmine oil (volume ratio 3:4:3). Moreover, the sum of the fractional inhibitory concentrations (Sigma fic) of preparation 1 expressed a synergistic antimicrobial effect against the tested microorganisms (Sigma fic

Characterization of Oaxaca raw milk cheese microbiota with particular interest in Lactobacillus strains.

PubMed

Caro, Irma; Mateo, Javier; Sandoval, María H; Soto, Sergio; García-Armesto, María R; Castro, José M

2013-06-01

The aim of this work was to identify and characterize lactobacilli strains from Mexican Oaxaca cheese. Twenty-seven lactobacilli isolated from Oaxaca cheese were identified at species level by 16S rRNA sequencing. Selected isolates were further characterized by ribotyping. Isolates were screened, among others, by acidifying capacity, antibiotic resistance, and activity against pathogens. Lactobacillus plantarum was predominant in Oaxaca cheese. The intraspecies variability of Lb. plantarum isolates was great. Multiple antibiotic resistances were observed. Eight isolates showed antimicrobial activity against the pathogenic species tested. Four Lb. plantarum strains showing low antibiotic resistance index, antimicrobial activity against enterotoxigenic Staphylococcus aureus and Listeria innocua stains, amine-negative decarboxylase activity, and resistance to NaCl and bile salt solutions, could be preselected to complete studies focused on designing a culture for use in pasteurized-milk Oaxaca cheese manufacturing. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Antimicrobial activity and partial characterization of bacteriocin-like inhibitory substances produced by Lactobacillus spp. isolated from artisanal Mexican cheese.

PubMed

Heredia-Castro, Priscilia Y; Méndez-Romero, José I; Hernández-Mendoza, Adrián; Acedo-Félix, Evelia; González-Córdova, Aarón F; Vallejo-Cordoba, Belinda

2015-12-01

Lactobacillus spp. from Mexican Cocido cheese were shown to produce bacteriocin-like substances (BLS) active against Staphylococcus aureus,Listeria innocua,Escherichia coli, andSalmonella typhimurium by using the disk diffusion method. Crude extracts of Lactobacillus fermentum showed strong inhibitory activity against Staph. aureus, L. innocua, E. coli, and Salmonella cholerae. Complete inactivation of antimicrobial activity was observed after treatment of crude extracts with proteinase K, pronase, papain, trypsin, and lysozyme, confirming their proteinaceous nature. However, antimicrobial activity was partly lost for some of the crude extracts when treated with α-amylase, indicating that carbohydrate moieties were involved. The antimicrobial activity of the crude extracts was stable at 65°C for 30min over a wide pH range (2-8), and addition of potassium chloride, sodium citrate, ethanol, and butanol did not affect antibacterial activity. However, antimicrobial activity was lost after heating at 121°C for 15min, addition of methanol or Tween 80. Fourteen out of 18 Lactobacillus spp. showed antimicrobial activity against different test microorganisms, and 12 presented bacteriocin-like substances. Generation time and growth rate parameters indicated that the antimicrobial activity of crude extracts from 3 different strains was effective against the 4 indicator microorganisms. One of the crude extracts showed inhibition not only against gram-positive but also against gram-negative bacteria. Bacteriocin-like substances produced by this specific Lactobacillus strain showed potential for application as a food biopreservative. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Opuntia ficus indica peel derived pectin mediated hydroxyapatite nanoparticles: synthesis, spectral characterization, biological and antimicrobial activities.

PubMed

Gopi, D; Kanimozhi, K; Kavitha, L

2015-04-15

In the present study, we have adapted a facile and efficient green route for the synthesis of HAP nanoparticles using pectin as a template which was extracted from the peel of prickly pear (Opuntia ficus indica) fruits. The concentration of pectin plays a major role in the behavior of crystallinity, purity, morphology as well as biological property of the as-synthesized HAP nanoparticles. The extracted pectin and the as-synthesized nanoparticles were characterized by various analytical techniques. The in vitro apatite formation on the surface of the as-synthesized nanoparticles in simulated body fluid (SBF) for various days showed an enhanced bioactivity. Also, the antimicrobial activity was investigated using various microorganisms. All the results revealed the formation of pure, low crystalline and discrete granular like HAP nanoparticles of size around 25 nm with enhanced biological and antimicrobial activities. Hence the as-synthesized nanoparticles can act as a better bone regenerating material in the field of biomedicine. Copyright © 2015 Elsevier B.V. All rights reserved.

Opuntia ficus indica peel derived pectin mediated hydroxyapatite nanoparticles: Synthesis, spectral characterization, biological and antimicrobial activities

NASA Astrophysics Data System (ADS)

Gopi, D.; Kanimozhi, K.; Kavitha, L.

2015-04-01

In the present study, we have adapted a facile and efficient green route for the synthesis of HAP nanoparticles using pectin as a template which was extracted from the peel of prickly pear (Opuntia ficus indica) fruits. The concentration of pectin plays a major role in the behavior of crystallinity, purity, morphology as well as biological property of the as-synthesized HAP nanoparticles. The extracted pectin and the as-synthesized nanoparticles were characterized by various analytical techniques. The in vitro apatite formation on the surface of the as-synthesized nanoparticles in simulated body fluid (SBF) for various days showed an enhanced bioactivity. Also, the antimicrobial activity was investigated using various microorganisms. All the results revealed the formation of pure, low crystalline and discrete granular like HAP nanoparticles of size around 25 nm with enhanced biological and antimicrobial activities. Hence the as-synthesized nanoparticles can act as a better bone regenerating material in the field of biomedicine.

Antimicrobial Activity Evaluation on Silver Doped Hydroxyapatite/Polydimethylsiloxane Composite Layer.

PubMed

Ciobanu, C S; Groza, A; Iconaru, S L; Popa, C L; Chapon, P; Chifiriuc, M C; Hristu, R; Stanciu, G A; Negrila, C C; Ghita, R V; Ganciu, M; Predoi, D

2015-01-01

The goal of this study was the preparation, physicochemical characterization, and microbiological evaluation of novel hydroxyapatite doped with silver/polydimethylsiloxane (Ag:HAp-PDMS) composite layers. In the first stage, the deposition of polydimethylsiloxane (PDMS) polymer layer on commercially pure Si disks has been produced in atmospheric pressure corona discharges. Finally, the new silver doped hydroxyapatite/polydimethylsiloxane composite layer has been obtained by the thermal evaporation technique. The Ag:HAp-PDMS composite layers were characterized by various techniques, such as Scanning Electron Microscopy (SEM), Glow Discharge Optical Emission Spectroscopy (GDOES), and X-ray photoelectron spectroscopy (XPS). The antimicrobial activity of the Ag:HAp-PDMS composite layer was assessed against Candida albicans ATCC 10231 (ATCC-American Type Culture Collection) by culture based and confirmed by SEM and Confocal Laser Scanning Microscopy (CLSM) methods. This is the first study reporting the antimicrobial effect of the Ag:HAp-PDMS composite layer, which proved to be active against Candida albicans biofilm embedded cells.

Antimicrobial Activity Evaluation on Silver Doped Hydroxyapatite/Polydimethylsiloxane Composite Layer

PubMed Central

Ciobanu, C. S.; Groza, A.; Iconaru, S. L.; Popa, C. L.; Chapon, P.; Chifiriuc, M. C.; Hristu, R.; Stanciu, G. A.; Negrila, C. C.; Ghita, R. V.; Ganciu, M.; Predoi, D.

2015-01-01

The goal of this study was the preparation, physicochemical characterization, and microbiological evaluation of novel hydroxyapatite doped with silver/polydimethylsiloxane (Ag:HAp-PDMS) composite layers. In the first stage, the deposition of polydimethylsiloxane (PDMS) polymer layer on commercially pure Si disks has been produced in atmospheric pressure corona discharges. Finally, the new silver doped hydroxyapatite/polydimethylsiloxane composite layer has been obtained by the thermal evaporation technique. The Ag:HAp-PDMS composite layers were characterized by various techniques, such as Scanning Electron Microscopy (SEM), Glow Discharge Optical Emission Spectroscopy (GDOES), and X-ray photoelectron spectroscopy (XPS). The antimicrobial activity of the Ag:HAp-PDMS composite layer was assessed against Candida albicans ATCC 10231 (ATCC—American Type Culture Collection) by culture based and confirmed by SEM and Confocal Laser Scanning Microscopy (CLSM) methods. This is the first study reporting the antimicrobial effect of the Ag:HAp-PDMS composite layer, which proved to be active against Candida albicans biofilm embedded cells. PMID:26504849

N-heterocyclic carbene metal complexes as bio-organometallic antimicrobial and anticancer drugs.

PubMed

Patil, Siddappa A; Patil, Shivaputra A; Patil, Renukadevi; Keri, Rangappa S; Budagumpi, Srinivasa; Balakrishna, Geetha R; Tacke, Matthias

2015-01-01

Late transition metal complexes that bear N-heterocyclic carbene (NHC) ligands have seen a speedy growth in their use as both, metal-based drug candidates and potentially active homogeneous catalysts in a plethora of C-C and C-N bond forming reactions. This review article focuses on the recent developments and advances in preparation and characterization of NHC-metal complexes (metal: silver, gold, copper, palladium, nickel and ruthenium) and their biomedical applications. Their design, syntheses and characterization have been reviewed and correlated to their antimicrobial and anticancer efficacies. All these initial discoveries help validate the great potential of NHC-metal derivatives as a class of effective antimicrobial and anticancer agents.

The role of diallyl sulfides and dipropyl sulfides in the in vitro antimicrobial activity of the essential oil of garlic, Allium sativum L., and leek, Allium porrum L.

PubMed

Casella, Sergio; Leonardi, Michele; Melai, Bernardo; Fratini, Filippo; Pistelli, Luisa

2013-03-01

The in vitro antibacterial activity of essential oils (EOs) obtained from fresh bulbs of garlic, Allium sativum L., and leek, Allium porrum L. ( Alliaceae), was studied. A. sativum (garlic) EO showed a good antimicrobial activity against Staphylococcus aureus (inhibition zone 14.8 mm), Pseudomonas aeruginosa (inhibition zone 21.1 mm), and Escherichia coli (inhibition zone 11.0 mm), whereas the EO of A. porrum (leek) had no antimicrobial activity. The main constituents of the garlic EO were diallyl monosulfide, diallyl disulfide (DADS), diallyl trisulfide, and diallyl tetrasulfide. The EO of A. porrum was characterized by the presence of dipropyl disulfide (DPDS), dipropyl trisulfide, and dipropyl tetrasulfide. The antimicrobial activities of the DADS and DPDS were also studied. The results obtained suggest that the presence of the allyl group is fundamental for the antimicrobial activity of these sulfide derivatives when they are present in Allium or in other species (DADS inhibition zone on S. aureus 15.9 mm, P. aeruginosa 21.9 mm, E. coli 11.4 mm). Copyright © 2012 John Wiley & Sons, Ltd.

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

PubMed

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.

Vaginal inserts based on chitosan and carboxymethylcellulose complexes for local delivery of chlorhexidine: preparation, characterization and antimicrobial activity.

PubMed

Bigucci, Federica; Abruzzo, Angela; Vitali, Beatrice; Saladini, Bruno; Cerchiara, Teresa; Gallucci, Maria Caterina; Luppi, Barbara

2015-01-30

The aim of this work was to prepare vaginal inserts based on chitosan/carboxymethylcellulose polyelectrolyte complexes for local delivery of chlorhexidine digluconate. Complexes were prepared with different chitosan/carboxymethylcellulose molar ratios at a pH value close to pKa interval of the polymers and were characterized in terms of physico-chemical properties, complexation yield and drug loading. Then complexes were used to prepare inserts as vaginal dosage forms and their physical handling, morphology, water-uptake ability and drug release properties as well as antimicrobial activity toward Candida albicans and Escherichia coli were evaluated. Results confirmed the ionic interaction between chitosan and carboxymethylcellulose and the influence of the charge amount on the complexation yield. Complexes were characterized by high values of drug loading and showed increasing water-uptake ability with the increase of carboxymethylcellulose amount. The selection of appropriate chitosan/carboxymethylcellulose molar ratios allowed to obtain cone-like shaped solid inserts, easy to handle and able to hydrate releasing the drug over time. Finally, the formulated inserts showed antimicrobial activity against common pathogens responsible for vaginal infections. Copyright © 2014 Elsevier B.V. All rights reserved.

Paederia foetida Linn. promoted biogenic gold and silver nanoparticles: Synthesis, characterization, photocatalytic and in vitro efficacy against clinically isolated pathogens.

PubMed

Bhuyan, Bishal; Paul, Arijita; Paul, Bappi; Dhar, Siddhartha Sankar; Dutta, Pranab

2017-08-01

Development of newer improved therapeutic agents with efficient antimicrobial activities continues to draw attention of researchers till date. Moreover, abatement of polluting dyes released from industry with enhanced efficiency is currently being considered as challenging task for people working on material sciences. In the present study, we report a facile biogenic synthesis of gold and silver nanoparticles (NPs) in which aqueous extracts of Paederia foetida Linn. was used as reducing as well as stabilizing agent. The biosynthesized Au and Ag NPs were characterized by UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The photocatalytic activity of these nanoparticles were tested against Rhodamine B (RhB). The antimicrobial activity of these biosynthesized NPs were investigated against four human pathogens viz. B. cereus, E. coli, S. aureus and A. niger. Biogenic silver nanoparticles presented a strong antimicrobial activity against B. cereus (26.13) followed by E. coli (26.02), S. aureus (25.43) and A. niger (22.69). Ag NPs owing to their small size (5-25nm) could have easily penetrate into the cell membrane, disturb the metabolism, cause irretrievable damage finally leading to the microbial cell death. Interestingly biogenic gold nanoparticles didn't show any antimicrobial activity. Copyright © 2017 Elsevier B.V. All rights reserved.

Biochemical and biological characterization of two Brassicaceae after their commercial expiry date.

PubMed

Ombra, Maria Neve; Cozzolino, Autilia; Nazzaro, Filomena; d'Acierno, Antonio; Tremonte, Patrizio; Coppola, Raffaele; Fratianni, Florinda

2017-03-01

Two Brassicaceae (Eruca sativa, Brassica oleracea var. sabauda) were stored in air and under a modified atmosphere for several days after their expiry date and then analyzed. The polyphenol content and composition, as well as the antioxidant activity of the extracts, were assessed, compared to the fresh products. Antimicrobial properties on tester strains (Bacillus cereus, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa) and in vitro anti-proliferative activity were evaluated. The cabbage extracts exhibited antimicrobial activity mainly on the ninth day after the expiry date and retained significant inhibitory effects against colon carcinoma (CaCo-2) cells. The rocket salad extract exhibited antiproliferative but not antimicrobial activity. Overall, our results indicated that they might represent a good source of natural antioxidants with antimicrobial and anti-proliferative activity, also after their expiry date, suggesting their exploitation for the recovery of important biomolecules used in the food and health industry. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preparation, characterization, and antimicrobial activity of nanoemulsions incorporating citral essential oil.

PubMed

Lu, Wen-Chien; Huang, Da-Wei; Wang, Chiun-C R; Yeh, Ching-Hua; Tsai, Jen-Chieh; Huang, Yu-Ting; Li, Po-Hsien

2018-01-01

Citral is a typical essential oil used in the food, cosmetic, and drug industries and has shown antimicrobial activity against microorganisms. Citral is unstable and hydrophobic under normal storage conditions, so it can easily lose its bactericide activity. Nanoemulsion technology is an excellent way to hydrophilize, microencapsulate, and protect this compound. In our studies, we used a mixed surfactant to form citral-in-water nanoemulsions, and attempted to optimize the formula for preparing nanoemulsions. Citral-in-water nanoemulsions formed at S o 0.4 to 0.6 and ultrasonic power of 18 W for 120 seconds resulted in a droplet size of < 100 nm for nanoemulsions. The observed antimicrobial activities were significantly affected by the formulation of the nanoemulsions. The observed relationship between the formulation and activity can lead to the rational design of nanoemulsion-based delivery systems for essential oils, based on the desired function of antimicrobials in the food, cosmetics, and agrochemical industries. Copyright © 2017. Published by Elsevier B.V.

Bioguided Fractionation Shows Cassia alata Extract to Inhibit Staphylococcus epidermidis and Pseudomonas aeruginosa Growth and Biofilm Formation

PubMed Central

Saito, Samuel Takashi; Trentin, Danielle da Silva; Macedo, Alexandre José; Pungartnik, Cristina; Gosmann, Grace; Silveira, Jaqueline de Deos; Guecheva, Temenouga Nikolova; Henriques, João Antonio Pêgas; Brendel, Martin

2012-01-01

Plant extracts have a long history to be used in folk medicine. Cassia alata extracts are known to exert antibacterial activity but details on compounds and mechanism of action remain poorly explored. We purified and concentrated the aqueous leaf extract of C. alata by reverse phase-solid phase extraction and screened the resulting CaRP extract for antimicrobial activity. CaRP extract exhibited antimicrobial activity for Pseudomonas aeruginosa, Staphylococcus epidermidis, S. aureus, and Bacillus subtilis. CaRP also inhibited biofilm formation of S. epidermidis and P. aeruginosa. Several bacterial growth-inhibiting compounds were detected when CaRP extract was fractionated by TLC chromatography coupled to bioautography agar overlay technique. HPLC chromatography of CaRP extract yielded 20 subfractions that were tested by bioautography for antimicrobial activity against S. aureus and S. epidermidis. Five bioactive fractions were detected and chemically characterized, using high-resolution mass spectrometry (qTOF-MS/MS). Six compounds from four fractions could be characterized as kaempferol, kaempferol-O-diglucoside, kaempferol-O-glucoside, quercetin-O-glucoside, rhein, and danthron. In the Salmonella/microsome assay CaRP showed weak mutagenicity (MI < 3) only in strain TA98, pointing to a frameshift mutation activity. These results indicate that C. alata leaf extract contains a minimum of 7 compounds with antimicrobial activity and that these together or as single substance are active in preventing formation of bacterial biofilm, indicating potential for therapeutic applications. PMID:22548121

Bioguided Fractionation Shows Cassia alata Extract to Inhibit Staphylococcus epidermidis and Pseudomonas aeruginosa Growth and Biofilm Formation.

PubMed

Saito, Samuel Takashi; Trentin, Danielle da Silva; Macedo, Alexandre José; Pungartnik, Cristina; Gosmann, Grace; Silveira, Jaqueline de Deos; Guecheva, Temenouga Nikolova; Henriques, João Antonio Pêgas; Brendel, Martin

2012-01-01

Plant extracts have a long history to be used in folk medicine. Cassia alata extracts are known to exert antibacterial activity but details on compounds and mechanism of action remain poorly explored. We purified and concentrated the aqueous leaf extract of C. alata by reverse phase-solid phase extraction and screened the resulting CaRP extract for antimicrobial activity. CaRP extract exhibited antimicrobial activity for Pseudomonas aeruginosa, Staphylococcus epidermidis, S. aureus, and Bacillus subtilis. CaRP also inhibited biofilm formation of S. epidermidis and P. aeruginosa. Several bacterial growth-inhibiting compounds were detected when CaRP extract was fractionated by TLC chromatography coupled to bioautography agar overlay technique. HPLC chromatography of CaRP extract yielded 20 subfractions that were tested by bioautography for antimicrobial activity against S. aureus and S. epidermidis. Five bioactive fractions were detected and chemically characterized, using high-resolution mass spectrometry (qTOF-MS/MS). Six compounds from four fractions could be characterized as kaempferol, kaempferol-O-diglucoside, kaempferol-O-glucoside, quercetin-O-glucoside, rhein, and danthron. In the Salmonella/microsome assay CaRP showed weak mutagenicity (MI < 3) only in strain TA98, pointing to a frameshift mutation activity. These results indicate that C. alata leaf extract contains a minimum of 7 compounds with antimicrobial activity and that these together or as single substance are active in preventing formation of bacterial biofilm, indicating potential for therapeutic applications.

The novel antimicrobial peptides from skin of Chinese broad-folded frog, Hylarana latouchii (Anura:Ranidae).

PubMed

Wang, Hui; Lu, Yi; Zhang, Xiuqing; Hu, Yuhong; Yu, Haining; Liu, Jingze; Sun, Junshe

2009-02-01

Broad-folded frogs (Hylarana latouchii), one member of 12 species of the genus Hylarana in the Chinese frog fauna, are widely distributed in the South of China. In this study, we purified and characterized three antimicrobial peptides from the skin secretion of H. latouchii. Five different cDNA fragments encoding the precursors of these antimicrobial peptides were cloned, and five mature antimicrobial peptides belonging to two different families were deduced from the five cDNAs. Structural characterization of the mature peptides had identified them as members of the brevinin-1 and temporin families. They were named brevinin-1LTa (FFGTALKIAANVLPTAICKILKKC), brevinin-1LTb (FFGTALKIAANILPTAICKILKKC), temporin-LTa (FFPLVLGALGSILPKIF-NH(2)), temporin-LTb (FIITGLVRGLTKLF-NH(2)) and temorin-LTc (SLSRFLSFLKIVYPPAF-NH(2)). Brevinin-1LTa, temporin-LTa, temporin-LTb and temporin-LTc with different antimicrobial activities induced significant morphological alterations of the tested microbial surfaces as shown by scanning electron microscopy, which indicated strong membrane disruption.

Identification and Characterization of Lactic Acid Bacteria in a Commercial Probiotic Culture

PubMed Central

MENCONI, Anita; KALLAPURA, Gopala; LATORRE, Juan D.; MORGAN, Marion J.; PUMFORD, Neil R.; HARGIS, Billy M.; TELLEZ, Guillermo

2014-01-01

The aim of the present study was to describe the identification and characterization (physiological properties) of two strains of lactic acid bacteria (LAB 18 and 48) present in a commercial probiotic culture, FloraMax®-B11. Isolates were characterized morphologically, and identified biochemically. In addition, the MIDI System ID, the Biolog ID System, and 16S rRNA sequence analyses for identification of LAB 18 and LAB 48 strains were used to compare the identification results. Tolerance and resistance to acidic pH, high osmotic concentration of NaCl, and bile salts were tested in broth medium. In vitro assessment of antimicrobial activity against enteropathogenic bacteria and susceptibility to antibiotics were also tested. The results obtained in this study showed tolerance of LAB 18 and LAB 48 to pH 3.0, 6.5% NaCl and a high bile salt concentration (0.6%). Both strains evaluated showed in vitro antibacterial activity against Salmonella enterica serovar Enteritidis, Escherichia coli (O157:H7), and Campylobacter jejuni. These are important characteristics of lactic acid bacteria that should be evaluated when selecting strains to be used as probiotics. Antimicrobial activity of these effective isolates may contribute to efficacy, possibly by direct antimicrobial activity in vivo. PMID:24936379

Purification and characterization of bacteriocin produced by oral Lactobacillus paracasei SD1.

PubMed

Wannun, P; Piwat, S; Teanpaisan, R

2014-06-01

The present study aimed to purify and characterize the antimicrobial protein from Lactobacillus paracasei SD1, which is a strain from the human oral cavity. Antimicrobial activity was obtained from purifying the culture supernatant of L. paracasei SD1. Purification of the active compound was achieved with ammonium sulfate precipitation followed by chloroform and gel filtration chromatography. As revealed by SDS-PAGE, the active fraction was homogeneous, showing a protein with an approximate molecular weight of 25,000 Da. It was confirmed as having a molecular mass of 24,028.2 Da by mass spectrometry. The antimicrobial compound, named "paracasin SD1", exhibited a broad spectrum against oral pathogens. Paracasin SD1 was stable in a pH range between 3.0 and 8.0 at 100 °C for 5 min, and showed resistance to α-amylase, catalase, lysozyme and whole saliva. However, its activity was lost after proteinase K and trypsin treatment. The results obtained suggest the possibility of using paracasin SD1 for application in prevention/treatment of oral diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Catesbeianin-1, a novel antimicrobial peptide isolated from the skin of Lithobates catesbeianus (American bullfrog).

PubMed

Xu, Huihui; Zhang, Yang; Feng, Xin; Tie, Kunyuan; Cao, Yuan; Han, Wenyu

2017-06-01

To identify and characterize a novel antimicrobial peptide, catesbeianin-1. Catesbeianin-1 is 25 amino acids long and is α-helical, cationic and amphipathic. It had antimicrobial activity against Gram-positive and Gram-negative bacteria. It was resistant against trypsin and pepsin. Catesbeianin-1 exhibited moderate hemolytic activity (approx 8%) at 100 μg/ml, and its HC 50 (50% hemolytic concentration) was 300 μg/ml. Its cytotoxicity was approx 10-20% at 100 μg/ml, and its CC 50 (50% cytotoxic concentration) was >100 μg/ml. The LD 50 of catesbeianin-1 in mice was 80 mg/kg. At 3.1 µg/ml, catesbeianin-1 significantly inhibited the growth of methicillin-resistant Staphylococcus aureus. A new antimicrobial peptide from the skin of Lithobates catesbeianus (American bullfrog) may represent a template for the development of novel antimicrobial agents.

Propolis--based chitosan varnish: drug delivery, controlled release and antimicrobial activity against oral pathogen bacteria.

PubMed

Franca, Juçara R; De Luca, Mariana P; Ribeiro, Tatiana G; Castilho, Rachel O; Moreira, Allyson N; Santos, Vagner R; Faraco, André A G

2014-12-12

Dental caries is the most prevalent oral disease in several Asian and Latin American countries. It is an infectious disease and different types of bacteria are involved in the process. Synthetic antimicrobials are used against this disease; however, many of these substances cause unwarranted undesirable effects like vomiting, diarrhea and tooth staining. Propolis, a resinous substance collected by honeybees, has been used to control the oral microbiota. So, the objective of this study was to develop and characterize sustained-release propolis-based chitosan varnish useful on dental cariogenic biofilm prevention, besides the in vitro antimicrobial activity. Three formulations of propolis - based chitosan varnish (PCV) containing different concentrations (5%, 10% and 15%) were produced by dissolution of propolis with chitosan on hydro-alcoholic vehicle. Bovine teeth were used for testing adhesion of coatings and to observe the controlled release of propolis associated with varnish. It was characterized by infrared spectroscopy, scanning electron microscopy, casting time, diffusion test in vitro antimicrobial activity and controlled release. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were tested for the main microorganisms involved in the cariogenic biofilm through the microdilution test in 96-well plates. The formulations presented a tooth surface adherence and were able to form films very fast on bovine tooth surface. Also, propolis-based chitosan varnishes have shown antimicrobial activity similar to or better than chlorhexidine varnish against all oral pathogen bacteria. All microorganisms were sensitive to propolis varnish and chitosan. MIC and MBC for microorganisms of cariogenic biofilme showed better results than chlorhexidine. Propolis active components were released for more than one week. All developed formulations turn them, 5%, 10% and 15% propolis content varnish, into products suitable for clinical application on dental caries prevention field, deserving clinical studies to confirm its in vivo activity.

Characteristics of Antimicrobial Stewardship Programs at Veterans Affairs Hospitals: Results of a Nationwide Survey.

PubMed

Chou, Ann F; Graber, Christopher J; Jones, Makoto; Zhang, Yue; Goetz, Matthew Bidwell; Madaras-Kelly, Karl; Samore, Matthew; Kelly, Allison; Glassman, Peter A

2016-06-01

BACKGROUND Antimicrobial stewardship programs (ASPs) are variably implemented. OBJECTIVE To characterize variations of antimicrobial stewardship structure and practices across all inpatient Veterans Affairs facilities in 2012 and correlate key characteristics with antimicrobial usage. DESIGN A web-based survey regarding stewardship activities was administered to each facility's designated contact. Bivariate associations between facility characteristics and inpatient antimicrobial use during 2012 were determined. SETTING Total of 130 Veterans Affairs facilities with inpatient services. RESULTS Of 130 responding facilities, 29 (22%) had a formal policy establishing an ASP, and 12 (9%) had an approved ASP business plan. Antimicrobial stewardship teams were present in 49 facilities (38%); 34 teams included a clinical pharmacist with formal infectious diseases (ID) training. Stewardship activities varied across facilities, including development of yearly antibiograms (122 [94%]), formulary restrictions (120 [92%]), stop orders for antimicrobial duration (98 [75%]), and written clinical pathways for specific conditions (96 [74%]). Decreased antimicrobial usage was associated with having at least 1 full-time ID physician (P=.03), an ID fellowship program (P=.003), and a clinical pharmacist with formal ID training (P=.006) as well as frequency of systematic patient-level reviews of antimicrobial use (P=.01) and having a policy to address antimicrobial use in the context of Clostridium difficile infection (P=.01). Stop orders for antimicrobial duration were associated with increased use (P=.03). CONCLUSIONS ASP-related activities varied considerably. Decreased antibiotic use appeared related to ID presence and certain select practices. Further statistical assessments may help optimize antimicrobial practices. Infect Control Hosp Epidemiol 2016;37:647-654.

Biosynthesis and characterization of Acalypha indica mediated copper oxide nanoparticles and evaluation of its antimicrobial and anticancer activity.

PubMed

Sivaraj, Rajeshwari; Rahman, Pattanathu K S M; Rajiv, P; Narendhran, S; Venckatesh, R

2014-08-14

Copper oxide nanoparticles were synthesized by biological method using aqueous extract of Acalypha indica leaf and characterized by UV-visible spectroscopy, XRD, FT-IR, SEM TEM and EDX analysis. The synthesised particles were highly stable, spherical and particle size was in the range of 26-30 nm. The antimicrobial activity of A.indica mediated copper oxide nanoparticles was tested against selected pathogens. Copper oxide nanoparticles showed efficient antibacterial and antifungal effect against Escherichia coli, Pseudomonas fluorescens and Candida albicans. The cytotoxicity activity of A.indica mediated copper nanoparticles was evaluated by MTT assay against MCF-7 breast cancer cell lines and confirmed that copper oxide nanoparticles have cytotoxicity activity. Copyright © 2014 Elsevier B.V. All rights reserved.

Optimized dispersion of ZnO nanoparticles and antimicrobial activity against foodborne pathogens and spoilage microorganisms

NASA Astrophysics Data System (ADS)

Espitia, Paula Judith Perez; Soares, Nilda de Fátima Ferreira; Teófilo, Reinaldo F.; Vitor, Débora M.; Coimbra, Jane Sélia dos Reis; de Andrade, Nélio José; de Sousa, Frederico B.; Sinisterra, Rubén D.; Medeiros, Eber Antonio Alves

2013-01-01

Single primary nanoparticles of zinc oxide (nanoZnO) tend to form particle collectives, resulting in loss of antimicrobial activity. This work studied the effects of probe sonication conditions: power, time, and the presence of a dispersing agent (Na4P2O7), on the size of nanoZnO particles. NanoZnO dispersion was optimized by response surface methodology (RSM) and characterized by the zeta potential (ZP) technique. NanoZnO antimicrobial activity was investigated at different concentrations (1, 5, and 10 % w/w) against four foodborne pathogens and four spoilage microorganisms. The presence of the dispersing agent had a significant effect on the size of dispersed nanoZnO. Minimum size after sonication was 238 nm. An optimal dispersion condition was achieved at 200 W for 45 min of sonication in the presence of the dispersing agent. ZP analysis indicated that the ZnO nanoparticle surface charge was altered by the addition of the dispersing agent and changes in pH. At tested concentrations and optimal dispersion, nanoZnO had no antimicrobial activity against Pseudomonas aeruginosa, Lactobacillus plantarum, and Listeria monocytogenes. However, it did have antimicrobial activity against Escherichia coli, Salmonella choleraesuis, Staphylococcus aureus, Saccharomyces cerevisiae, and Aspergillus niger. Based on the exhibited antimicrobial activity of optimized nanoZnO against some foodborne pathogens and spoilage microorganisms, nanoZnO is a promising antimicrobial for food preservation with potential application for incorporation in polymers intended as food-contact surfaces.

Structural characterization and antimicrobial activities of transition metal complexes of a hydrazone ligand

NASA Astrophysics Data System (ADS)

Bakale, Raghavendra P.; Naik, Ganesh N.; Machakanur, Shrinath S.; Mangannavar, Chandrashekhar V.; Muchchandi, Iranna S.; Gudasi, Kalagouda B.

2018-02-01

A hydrazone ligand has been synthesized by the condensation of 2-nitrobenzaldehyde and hydralazine, and its Co(II), Ni(II), Cu(II) and Zn(II) complexes have been reported. Structural characterization of the ligand and its metal complexes has been performed by various spectroscopic [IR, NMR, UV-Vis, Mass], thermal and other physicochemical methods. The structure of the ligand and its Ni(II) complex has been characterized by single crystal X-ray diffraction studies. All the synthesized compounds have been screened for in vitro antimicrobial activity. The antibacterial activity is tested against Gram-positive strains Enterococcus faecalis, Streptococcus mutans and Staphylococcus aureus and Gram-negative strains Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae using ciprofloxacin as the reference standard. Antifungal activity is tested against Candida albicans, Aspergillus fumigatus and Aspergillus niger using ketoconazole as the reference standard. The minimum inhibitory concentration (MIC) was determined for test compounds as well as for reference standard. Ligand, Cu(II) and Zn(II) complexes have shown excellent activity against Candida albicans.

Tuned apatitic materials: Synthesis, characterization and potential antimicrobial applications

NASA Astrophysics Data System (ADS)

Fierascu, Irina; Fierascu, Radu Claudiu; Somoghi, Raluca; Ion, Rodica Mariana; Moanta, Adriana; Avramescu, Sorin Marius; Damian, Celina Maria; Ditu, Lia Mara

2018-04-01

Inorganic antimicrobial materials can be viable for multiple applications (related to its use for new buildings with special requirements related to microbiological loading, such as hospital buildings and for consolidation of cultural heritage constructions); also the use of substituted hydroxyapatites for protection of stone artefacts against environmental factors (acidic rain) and biodeterioration it's an option to no longer use of toxic substances. This paper presents methods of synthesis and characterization of the material from the point of view of the obtained structures and final applications. The materials were characterized in terms of composition and morphology (using X-ray Diffraction, X-ray Fluorescence, Inductively coupled plasma-atomic emission spectrometry, Fourier Transform Infrared Spectroscopy, X-ray Photoelectron Spectroscopy, Surface area and pore size determination). Antimicrobial activity was tested against filamentous fungi strains and pathogenic bacteria strains, using both spot on lawn qualitative method (on agar medium) and serial microdilution quantitative method (in broth medium). Further, it was evaluated the anti-biofilm activity of the tested samples toward the most important microbial strains implicated in biofilm development, using crystal violet stained biofilms microtiter assay, followed by spectrophotometric quantitative evaluation.

The antimicrobial efficacy of sustained release silver–carbene complex-loaded l-tyrosine polyphosphate nanoparticles: Characterization, in vitro and in vivo studies

PubMed Central

Hindi, Khadijah M.; Ditto, Andrew J.; Panzner, Matthew J.; Medvetz, Douglas A.; Han, Daniel S.; Hovis, Christine E.; Hilliard, Julia K.; Taylor, Jane B.; Yun, Yang H.; Cannon, Carolyn L.; Youngs, Wiley J.

2009-01-01

The pressing need to treat multi-drug resistant bacteria in the chronically infected lungs of cystic fibrosis (CF) patients has given rise to novel nebulized antimicrobials. We have synthesized a silver–carbene complex (SCC10) active against a variety of bacterial strains associated with CF and chronic lung infections. Our studies have demonstrated that SCC10-loaded into l-tyrosine polyphosphate nanoparticles (LTP NPs) exhibits excellent antimicrobial activity in vitro and in vivo against the CF relevant bacteria Pseudomonas aeruginosa. Encapsulation of SCC10 in LTP NPs provides sustained release of the antimicrobial over the course of several days translating into efficacious results in vivo with only two administered doses over a 72 h period. PMID:19395021

Chemical composition and antimicrobial activity of the essential oil of Juniperus excelsa M.Bieb. growing wild in Lebanon.

PubMed

Khoury, Madona; El Beyrouthy, Marc; Ouaini, Naïm; Iriti, Marcello; Eparvier, Véronique; Stien, Didier

2014-05-01

The essential oils (EOs) isolated from the leaves and twigs of Juniperus excelsa M.Bieb. growing wild in Lebanon were characterized, and their antimicrobial activity and antiradical capacity were evaluated. The EOs were obtained by hydrodistillation using a Clevenger-type apparatus and characterized by GC and GC/MS analyses. The antimicrobial activity was evaluated by determining minimal inhibitory concentrations (MICs) against a Gram-positive and a Gram-negative bacterium, a yeast, and a dermatophyte with the broth microdilution technique. A total of 28 constituents was identified and accounted for 90.1 and 95.6% of the twig and leaf EO composition, respectively. Both EOs were essentially composed of monoterpene hydrocarbons (46.7 and 59.6% for twig and leaf EOs, resp.) and sesquiterpenes (39.4 and 32.1%, resp.). The main components were α-pinene, α-cedrol, and δ-car-3-ene. The J. excelsa EOs did not show any antiradical potential, but revealed interesting in vitro antimicrobial activities against Staphylococcus aureus and Trichophyton rubrum (MICs of 64 and 128 μg/ml, resp.). The three major compounds were tested separately and in combination according to their respective amounts in the oil. δ-Car-3-ene was the most active component and is undoubtedly one of the constituents driving the antifungal activity of J. excelsa essential oil, even though synergies are probably involved. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

Molecular Characterization and Analysis of Antimicrobial Activity of Endophytic Fungi From Medicinal Plants in Saudi Arabia

PubMed Central

Gashgari, Rukaia; Gherbawy, Youssuf; Ameen, Fuad; Alsharari, Salam

2016-01-01

Background: Endophytic fungi, which have been reported in numerous plant species, are important components of the forest community and contribute significantly to the diversity of natural ecosystems. Objectives: The current study aimed to evaluate and characterize, at the molecular level, the diversity and antimicrobial activities of endophytic fungi from medicinal plants in Saudi Arabia. Materials and Methods: Fungi growing on plant segments were isolated and identified based on morphological and molecular characteristics. The isolates were grouped into 35 distinct operational taxonomic units, based on the sequence of the internal transcribed spacer regions in the rRNA gene. The colonization frequency and the dominant fungi percentage of these endophytic fungi were calculated. A dual culture technique was adopted to investigate the antifungal activity of these endophytes. Results: Tamarix nilotica showed the highest endophytic diversity with a relative frequency of 27.27%, followed by Cressa cretica with a relative frequency of 19.27%. The most frequently isolated species was Penicillium chrysogenum with an overall colonization rate of 98.57%. Seven out of 35 endophytic fungi exhibited strong antifungal activity to all plant fungal pathogens tested. P. chrysogenum, Fusarium oxysporum, and F. nygamai exhibited the highest inhibition against the human pathogenic bacteria Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Aspergillus sydowii, P. chrysogenum, and Eupenicillium crustaceum showed strong antimicrobial activity against Enterococcus faecalis. Conclusions: The antimicrobial activity of these endophytic microorganisms could be exploited in biotechnology, medicine, and agriculture. PMID:27099679

Unsaturated fatty acids lactose esters: cytotoxicity, permeability enhancement and antimicrobial activity.

PubMed

Lucarini, Simone; Fagioli, Laura; Campana, Raffaella; Cole, Hannah; Duranti, Andrea; Baffone, Wally; Vllasaliu, Driton; Casettari, Luca

2016-10-01

Sugar based surfactants conjugated with fatty acid chains are an emerging broad group of highly biocompatible and biodegradable compounds with established and potential future applications in the pharmaceutical, cosmetic and food industries. In this work, we investigated absorption enhancing and antimicrobial properties of disaccharide lactose, monoesterified with unsaturated fatty acids through an enzymatic synthetic approach. After chemical and cytotoxicity characterizations, their permeability enhancing activity was demonstrated using intestinal Caco-2 monolayers through transepithelial electrical resistance (TEER) and permeability studies. The synthesized compounds, namely lactose palmitoleate (URB1076) and lactose nervonate (URB1077), were shown to exhibit antimicrobial activity versus eight pathogenic species belonging to Gram-positive, Gram-negative microorganisms and fungi. Copyright © 2016 Elsevier B.V. All rights reserved.

Bi-Functional Biobased Packing of the Cassava Starch, Glycerol, Licuri Nanocellulose and Red Propolis

PubMed Central

Costa, Samantha Serra; Druzian, Janice Izabel; Machado, Bruna Aparecida Souza; de Souza, Carolina Oliveira; Guimarães, Alaíse Gil

2014-01-01

The aim of this study was to characterize and determine the bi-functional efficacy of active packaging films produced with starch (4%) and glycerol (1.0%), reinforced with cellulose nanocrystals (0–1%) and activated with alcoholic extracts of red propolis (0.4 to 1.0%). The cellulose nanocrystals used in this study were extracted from licuri leaves. The films were characterized using moisture, water-activity analyses and water vapor-permeability tests and were tested regarding their total phenolic compounds and mechanical properties. The antimicrobial and antioxidant efficacy of the films were evaluated by monitoring the use of the active films for packaging cheese curds and butter, respectively. The cellulose nanocrystals increased the mechanical strength of the films and reduced the water permeability and water activity. The active film had an antimicrobial effect on coagulase-positive staphylococci in cheese curds and reduced the oxidation of butter during storage. PMID:25383783

Bi-functional biobased packing of the cassava starch, glycerol, licuri nanocellulose and red propolis.

PubMed

Costa, Samantha Serra; Druzian, Janice Izabel; Machado, Bruna Aparecida Souza; de Souza, Carolina Oliveira; Guimarães, Alaíse Gil

2014-01-01

The aim of this study was to characterize and determine the bi-functional efficacy of active packaging films produced with starch (4%) and glycerol (1.0%), reinforced with cellulose nanocrystals (0-1%) and activated with alcoholic extracts of red propolis (0.4 to 1.0%). The cellulose nanocrystals used in this study were extracted from licuri leaves. The films were characterized using moisture, water-activity analyses and water vapor-permeability tests and were tested regarding their total phenolic compounds and mechanical properties. The antimicrobial and antioxidant efficacy of the films were evaluated by monitoring the use of the active films for packaging cheese curds and butter, respectively. The cellulose nanocrystals increased the mechanical strength of the films and reduced the water permeability and water activity. The active film had an antimicrobial effect on coagulase-positive staphylococci in cheese curds and reduced the oxidation of butter during storage.

Chitin and chitosan from the Norway lobster by-products: Antimicrobial and anti-proliferative activities.

PubMed

Sayari, Nadhem; Sila, Assaâd; Abdelmalek, Baha Eddine; Abdallah, Rihab Ben; Ellouz-Chaabouni, Semia; Bougatef, Ali; Balti, Rafik

2016-06-01

Chitin was recovered through enzymatic deproteinization of the Norway lobster (Nephrops norvegicus) processing by-products. The obtained chitin was characterized and converted into chitosan by N-deacetylation, the acid-soluble form of chitin. Chitosan samples were then characterized by Fourier transform infrared spectroscopy (FTIR) and 13 Cross polarization magic angle spinning nuclear magnetic resonance (CP/MAS)-NMR spectroscopy. The antimicrobial activity and anti-proliferative capacity of chitosan were evaluated. Antimicrobial activity assays indicated that prepared chitosan exhibited marked inhibitory activity against the bacterial and fungal strains tested. Further, cytotoxic effects of chitosan samples on human colon carcinoma cells HCT116 was evaluated using the MTT assay. Chitosan showed the antiproliferative capacity against the colon-cancer-cell HCT116 in a dose dependent manner with IC50 of 4.6mg/ml. Indeed, HCT116 cell proliferation was significantly inhibited (p<0.05) between 13.5 and 67.5% at 0.5-6mg/mL of chitosan after 24h of cell treatment. The chitosan showed high antitumor activity which seemed to be dependent on its characteristics such as acetylation degree. Copyright © 2016 Elsevier B.V. All rights reserved.

Incorporation of nisin in poly (ethylene-co-vinyl acetate) films by melt processing: a study on the antimicrobial properties.

PubMed

Scaffaro, Roberto; Botta, Luigi; Marineo, Sandra; Puglia, Anna Maria

2011-07-01

Both industry and academia have shown a growing interest in materials with antimicrobial properties suitable for food packaging applications. In this study, we prepared and characterized thin films of ethylene-co-vinyl acetate (EVA) copolymer with antimicrobial properties. The films were prepared with a film blowing process by incorporating a nisin preparation as an antimicrobial agent in the melt. Two grades of EVA containing 14 and 28% (wt/wt) vinyl acetate (EVA 14 and EVA 28, respectively) and two commercial formulations of nisin with different nominal activities were used. The effect of the nisin concentration also was evaluated. The films with the highest antimicrobial activity were those formulated with nisin at the highest activity and EVA with the highest content of vinyl acetate. The use of the commercial formulation of nisin with high activity in the EVA films allowed reduction in the amount of nisin needed to provide antimicrobial properties. Consequently, the mechanical properties of these films were only slightly inferior to those of the pure polymers. In contrast, films prepared by incorporating more of the nisin with lower activity had poor mechanical properties. The effect of different processing temperatures used in the preparation of the films on the antimicrobial properties of the films also was evaluated. The materials displayed antimicrobial properties even when they were prepared at temperatures as high as 160 °C, probably because of the very short processing time (60 to 90 s) required for preparation. Copyright ©, International Association for Food Protection

Isolation and Identification of Phyllospheric Bacteria Possessing Antimicrobial Activity from Astragalus obtusifolius, Prosopis juliflora, Xanthium strumarium and Hippocrepis unisiliqousa

PubMed Central

Mazinani, Zohreh; Zamani, Marzieh

2017-01-01

Background: The widespread utilization of antimicrobial compounds has caused emergence of resistant microorganisms in the world. Hence, the research to probe the products with antimicrobial features has led to finding natural habitats and discovering new pharmaceutical products. Methods: In this study, an attempt was made to explore the niche of novel habitat to isolate pyllospheric bacteria from the above ground parts (stems and leaves) of Astragalus obtusifolius, Prosopis juliflora, Xanthium strumarium, and Hippocrepis unisiliqousa to evaluate their antimicrobial features. The inhibitory effects of these strains on the growth of two fungi (Aspergillus niger, Aspergillus fumigatus), two yeasts (Saccharomyces cerevisiae, Candida albicans) and six bacteria (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Salmonella typhi, Streptococcus pyogenes) were tested. Results: In total, 113 bacterial strains were isolated. Twenty five bacterial strains (B-1 to B-25) indicated promising antimicrobial (antibacterial and antifungal) activities against aforementioned pathogens. The identification of the bacterial strains was ascertained by morphological, physiological, biochemical tests and two strains with the strongest antimicrobial activities were further characterized based on 16s rRNA sequencing. These two strains were identified as Bacillus amyloliquefaciens. Conclusion: Our results provide evidence that phyllospheric microorganisms are capable of producing some compounds with antimicrobial properties. PMID:28090278

Isolation and Identification of Phyllospheric Bacteria Possessing Antimicrobial Activity from Astragalus obtusifolius, Prosopis juliflora, Xanthium strumarium and Hippocrepis unisiliqousa.

PubMed

Mazinani, Zohreh; Zamani, Marzieh; Sardari, Soroush

2017-01-01

The widespread utilization of antimicrobial compounds has caused emergence of resistant microorganisms in the world. Hence, the research to probe the products with antimicrobial features has led to finding natural habitats and discovering new pharmaceutical products. In this study, an attempt was made to explore the niche of novel habitat to isolate pyllospheric bacteria from the above ground parts (stems and leaves) of Astragalus obtusifolius , Prosopis juliflora , Xanthium strumarium , and Hippocrepis unisiliqousa to evaluate their antimicrobial features. The inhibitory effects of these strains on the growth of two fungi ( Aspergillus niger , Aspergillus fumigatus ), two yeasts ( Saccharomyces cerevisiae , Candida albicans ) and six bacteria ( Escherichia coli , Staphylococcus aureus , Pseudomonas aeruginosa , Bacillus subtilis , Salmonella typhi , Streptococcus pyogenes ) were tested. In total, 113 bacterial strains were isolated. Twenty five bacterial strains (B-1 to B-25) indicated promising antimicrobial (antibacterial and antifungal) activities against aforementioned pathogens. The identification of the bacterial strains was ascertained by morphological, physiological, biochemical tests and two strains with the strongest antimicrobial activities were further characterized based on 16s rRNA sequencing. These two strains were identified as Bacillus amyloliquefaciens . Our results provide evidence that phyllospheric microorganisms are capable of producing some compounds with antimicrobial properties.

Isolation and identification of antimicrobial compound from Mentha longifolia L. leaves grown wild in Iraq.

PubMed

Al-Bayati, Firas A

2009-06-12

Mentha longifolia L. (Lamiaceae) leaves have been traditionally implemented in the treatment of minor sore throat and minor mouth or throat irritation by the indigenous people of Iraq, although the compounds responsible for the medicinal properties have not been identified. In the present study, an antimicrobial compound was isolated and characterized, and its biological activity was assessed. The compound was isolated and characterized from the extracted essential oil using different spectral techniques: TLC, FTIR spectra and HPLC. Antimicrobial activity of the compound was assessed using both disc diffusion and microdilution method in 96 multi-well microtiter plates. A known compound was isolated from the essential oil of the plant and was identified as (-) menthol. The isolated compound was investigated for its antimicrobial activity against seven selected pathogenic and non-pathogenic microorganisms: Staphylococcus aureus, Streptococcus mutans, Streptococcus faecalis, Streptococcus pyogenis, Lactobacillus acidophilus, Pseudomonas aeruginosa and the yeast Candida albicans. Menthol at different concentrations (1:1, 1:5, 1:10, 1:20) was active against all tested bacteria except for P. aeruginosa, and the highest inhibitory effect was observed against S. mutans (zone of inhibition: 25.3 mm) using the disc diffusion method. Minimal inhibitory concentration MIC values ranged from 15.6-125.0 microg/ml, and the most promising results were observed against S. aureus and S. mutans (MIC 15.6 microg/ml) while, S. faecalis, S. pyogenis and L. acidophilus ranked next (MIC 31.2 microg/ml). Furthermore, menthol achieved considerable antifungal activity against the yeast C. albicans (zone of inhibition range: 7.1-18.5 mm; MIC: 125.0). The isolation of an antimicrobial compound from M. longifolia leaves validates the use of this plant in the treatment of minor sore throat and minor mouth or throat irritation.

Preparation, characterization and in vitro antimicrobial activity of liposomal ceftazidime and cefepime against Pseudomonas aeruginosa strains

PubMed Central

Torres, Ieda Maria Sapateiro; Bento, Etiene Barbosa; Almeida, Larissa da Cunha; de Sá, Luisa Zaiden Carvalho Martins; Lima, Eliana Martins

2012-01-01

Pseudomonas aeruginosa is an opportunistic microorganism with the ability to respond to a wide variety of environmental changes, exhibiting a high intrinsic resistance to a number of antimicrobial agents. This low susceptibility to antimicrobial substances is primarily due to the low permeability of its outer membrane, efflux mechanisms and the synthesis of enzymes that promote the degradation of these drugs. Cephalosporins, particularty ceftazidime and cefepime are effective against P. aeruginosa, however, its increasing resistance has limited the usage of these antibiotics. Encapsulating antimicrobial drugs into unilamellar liposomes is an approach that has been investigated in order to overcome microorganism resistance. In this study, antimicrobial activity of liposomal ceftazidime and cefepime against P. aeruginosa ATCC 27853 and P. aeruginosa SPM-1 was compared to that of the free drugs. Liposomal characterization included diameter, encapsulation efficiency and stability. Minimum Inhibitory Concentration (MIC) was determined for free and liposomal forms of both drugs. Minimum Bactericidal Concentration (MBC) was determined at concentrations 1, 2 and 4 times MIC. Average diameter of liposomes was 131.88 nm and encapsulation efficiency for cefepime and ceftazidime were 2.29% end 5.77%, respectively. Improved stability was obtained when liposome formulations were prepared with a 50% molar ratio for cholesterol in relation to the phospholipid. MIC for liposomal antibiotics for both drugs were 50% lower than that of the free drug, demonstrating that liposomal drug delivery systems may contribute to increase the antibacterial activity of these drugs. PMID:24031917

Antimicrobial Properties of Biofunctionalized Silver Nanoparticles on Clinical Isolates of Streptococcus mutans and Its Serotypes

PubMed Central

Martínez-Robles, Ángel Manuel; Loyola-Rodríguez, Juan Pablo; Zavala-Alonso, Norma Verónica; Martinez-Martinez, Rita Elizabeth; Ruiz, Facundo; Lara-Castro, René Homero; Donohué-Cornejo, Alejandro; Reyes-López, Simón Yobanny; Espinosa-Cristóbal, León Francisco

2016-01-01

(1) Background: Streptococcus mutans (S. mutans) is the principal pathogen involved in the formation of dental caries. Other systemic diseases have also been associated with specific S. mutans serotypes (c, e, f, and k). Silver nanoparticles (SNP) have been demonstrated to have good antibacterial effects against S. mutans; therefore, limited studies have evaluated the antimicrobial activity of biofunctionalized SNP on S. mutans serotypes. The purpose of this work was to prepare and characterize coated SNP using two different organic components and to evaluate the antimicrobial activity of SNP in clinical isolates of S. mutans strains and serotypes; (2) Methods: SNP with bovine serum albumin (BSA) or chitosan (CS) coatings were prepared and the physical, chemical and microbiological properties of SNP were evaluated; (3) Results: Both types of coated SNP showed antimicrobial activity against S. mutans bacteria and serotypes. Better inhibition was associated with smaller particles and BSA coatings; however, no significant differences were found between the different serotypes, indicating a similar sensitivity to the coated SNP; (4) Conclusion: This study concludes that BSA and CS coated SNP had good antimicrobial activity against S. mutans strains and the four serotypes, and this study suggest the widespread use of SNP as an antimicrobial agent for the inhibition of S. mutans bacteria. PMID:28335264

Antimicrobial Properties of Biofunctionalized Silver Nanoparticles on Clinical Isolates of Streptococcus mutans and Its Serotypes.

PubMed

Martínez-Robles, Ángel Manuel; Loyola-Rodríguez, Juan Pablo; Zavala-Alonso, Norma Verónica; Martinez-Martinez, Rita Elizabeth; Ruiz, Facundo; Lara-Castro, René Homero; Donohué-Cornejo, Alejandro; Reyes-López, Simón Yobanny; Espinosa-Cristóbal, León Francisco

2016-07-22

(1) Background: Streptococcus mutans ( S. mutans ) is the principal pathogen involved in the formation of dental caries. Other systemic diseases have also been associated with specific S. mutans serotypes ( c , e , f , and k ). Silver nanoparticles (SNP) have been demonstrated to have good antibacterial effects against S. mutans ; therefore, limited studies have evaluated the antimicrobial activity of biofunctionalized SNP on S. mutans serotypes. The purpose of this work was to prepare and characterize coated SNP using two different organic components and to evaluate the antimicrobial activity of SNP in clinical isolates of S. mutans strains and serotypes; (2) Methods: SNP with bovine serum albumin (BSA) or chitosan (CS) coatings were prepared and the physical, chemical and microbiological properties of SNP were evaluated; (3) Results: Both types of coated SNP showed antimicrobial activity against S. mutans bacteria and serotypes. Better inhibition was associated with smaller particles and BSA coatings; however, no significant differences were found between the different serotypes, indicating a similar sensitivity to the coated SNP; (4) Conclusion: This study concludes that BSA and CS coated SNP had good antimicrobial activity against S. mutans strains and the four serotypes, and this study suggest the widespread use of SNP as an antimicrobial agent for the inhibition of S. mutans bacteria.

Streptomyces lunalinharesii strain 235 shows the potential to inhibit bacteria involved in biocorrosion processes.

PubMed

Pacheco da Rosa, Juliana; Korenblum, Elisa; Franco-Cirigliano, Marcella Novaes; Abreu, Fernanda; Lins, Ulysses; Soares, Rosângela M A; Macrae, Andrew; Seldin, Lucy; Coelho, Rosalie R R

2013-01-01

Four actinomycete strains previously isolated from Brazilian soils were tested for their antimicrobial activity against Bacillus pumilus LF-4 and Desulfovibrio alaskensis NCIMB 13491, bacteria that are well known to be involved in biofilm formation and biocorrosion. Strain 235, belonging to the species Streptomyces lunalinharesii, inhibited the growth of both bacteria. The antimicrobial activity was seen over a wide range of pH, and after treatment with several chemicals and heat but not with proteinase K and trypsin. The antimicrobial substances present in the concentrated supernatant from growth media were partially characterized by SDS-PAGE and extracellular polypeptides were seen. Bands in the size range of 12 to 14.4 kDa caused antimicrobial activity. Transmission electron microscopy of D. alaskensis cells treated with the concentrated supernatant containing the antimicrobial substances revealed the formation of prominent bubbles, the spherical double-layered structures on the cell membrane, and the periplasmic space completely filled with electron-dense material. This is the first report on the production of antimicrobial substances by actinomycetes against bacteria involved in biocorrosion processes, and these findings may be of great relevance as an alternative source of biocides to those currently employed in the petroleum industry.

Streptomyces lunalinharesii Strain 235 Shows the Potential to Inhibit Bacteria Involved in Biocorrosion Processes

PubMed Central

Pacheco da Rosa, Juliana; Korenblum, Elisa; Franco-Cirigliano, Marcella Novaes; Abreu, Fernanda; Lins, Ulysses; Soares, Rosângela M. A.; Macrae, Andrew; Seldin, Lucy; Coelho, Rosalie R. R.

2013-01-01

Four actinomycete strains previously isolated from Brazilian soils were tested for their antimicrobial activity against Bacillus pumilus LF-4 and Desulfovibrio alaskensis NCIMB 13491, bacteria that are well known to be involved in biofilm formation and biocorrosion. Strain 235, belonging to the species Streptomyces lunalinharesii, inhibited the growth of both bacteria. The antimicrobial activity was seen over a wide range of pH, and after treatment with several chemicals and heat but not with proteinase K and trypsin. The antimicrobial substances present in the concentrated supernatant from growth media were partially characterized by SDS-PAGE and extracellular polypeptides were seen. Bands in the size range of 12 to 14.4 kDa caused antimicrobial activity. Transmission electron microscopy of D. alaskensis cells treated with the concentrated supernatant containing the antimicrobial substances revealed the formation of prominent bubbles, the spherical double-layered structures on the cell membrane, and the periplasmic space completely filled with electron-dense material. This is the first report on the production of antimicrobial substances by actinomycetes against bacteria involved in biocorrosion processes, and these findings may be of great relevance as an alternative source of biocides to those currently employed in the petroleum industry. PMID:23484107

Isolation, purification and characterization of antimicrobial protein from seedlings of Bauhinia purpurea L.

PubMed

Sakthivel, Muthu; Palani, Perumal

2016-05-01

A novel antimicrobial protein was purified from the seedlings of Bauhinia purpurea by sequential procedures entailing ammonium sulfate precipitation, cation exchange chromatography, preparative native-PAGE and a yield of 2.7% was obtained from the crude extract. The purified antimicrobial protein appeared as a single protein band on SDS-PAGE with the molecular mass of 20.9 kDa. Purified antimicrobial protein exhibited a potent antimicrobial activity against both Gram-positive and Gram-negative bacteria. Analysis of the trypsin digested peptides of purified protein using the MALDI-TOF MS/MS resulted in the identification of 174 amino acids. The purified protein had an optimum of pH of 5.5 and was stable at 35 °C for exhibiting its maximal antibacterial activity. The addition of metal ions such as Mn(2+) and Ca(2+) to the purified protein enhanced the antimicrobial activity of purified protein. The MIC of purified protein against Bacillus cereus and Escherichia coli were 13 μg/ml and 15 μg/ml, respectively. The purified protein digested the peptidoglycan layer of bacteria which was visualized by TEM analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis, Spectral investigation (¹H, ¹³C) and Anti-microbial Screening of benzophenone imines.

PubMed

Khosa, Muhammad Kaleem; Jamal, Muhammad Asghar; Saif, Muhammad Jawad; Muneer, Majid; Rehman, Fazalur; Farman, Muhammad; Shoaib, Hafiz Muhammad; Shahid, Muhammad; Hameed, Shabnam

2015-11-01

New series of benzophenone imines with general formula Ph2-C=NR; R = Benzyl, 4-Fluorobenzyl, Naphthyl, Phenyl, 4-Nitrophenyl were synthesized by condensation of dichlorodiphenylmethane and different aromatic primary amines (1:1) Those imines were characterized by different physiochemical and spectroscopic techniques like melting point, elemental analysis, FT-IR, multinuclear NMR (¹H, ¹³C). After characterization, imines were subjected to anti-microbial activities. All compounds showed promising activity against different bacterial strains like Escherichia coli, Bacillussubtilis, Pasturellam ultocida and Staphylococcus aureus as well as fungal strains like Alternata alternaria, Ganoderma lucidium, Penicillium notatum and Trichoderma harzianum using Amoxicillin and Flucanazole as a standard drugs respectively.

A series of novel oxovanadium(IV) complexes: Synthesis, spectral characterization and antimicrobial study

NASA Astrophysics Data System (ADS)

Sahani, M. K.; Pandey, S. K.; Pandey, O. P.; Sengupta, S. K.

2014-09-01

Oxovanadium(IV) complexes have been synthesized by reacting vanadyl sulfate with Schiff bases derived from 4-amino-5-(substitutedphenoxyacetic acid)-1,2,4-triazole-3-thiol and benzil. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non-electrolytes and characterized by elemental analysis, spectral techniques (UV-Vis, IR, EPR and XRD) and magnetic moment measurements. The EPR spectra indicate that the free electron is in dxy orbital. In vitro antifungal activity of ligands and synthesized compounds was determined against fungi Aspergillus niger, Colletotrichum falcatum and Colletotrichum pallescence and in vitro antibacterial activity was determined by screening the compounds against Gram-negative (Escherichia coli and Salmonella typhi) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacterial strains. The antimicrobial activities have shown that the activity increases upon complexation.

The Alzheimer's Disease-Associated Amyloid β-Protein Is an Antimicrobial Peptide

PubMed Central

Soscia, Stephanie J.; Kirby, James E.; Washicosky, Kevin J.; Tucker, Stephanie M.; Ingelsson, Martin; Hyman, Bradley; Burton, Mark A.; Goldstein, Lee E.; Duong, Scott; Tanzi, Rudolph E.; Moir, Robert D.

2010-01-01

Background The amyloid β-protein (Aβ) is believed to be the key mediator of Alzheimer's disease (AD) pathology. Aβ is most often characterized as an incidental catabolic byproduct that lacks a normal physiological role. However, Aβ has been shown to be a specific ligand for a number of different receptors and other molecules, transported by complex trafficking pathways, modulated in response to a variety of environmental stressors, and able to induce pro-inflammatory activities. Methodology/Principal Findings Here, we provide data supporting an in vivo function for Aβ as an antimicrobial peptide (AMP). Experiments used established in vitro assays to compare antimicrobial activities of Aβ and LL-37, an archetypical human AMP. Findings reveal that Aβ exerts antimicrobial activity against eight common and clinically relevant microorganisms with a potency equivalent to, and in some cases greater than, LL-37. Furthermore, we show that AD whole brain homogenates have significantly higher antimicrobial activity than aged matched non-AD samples and that AMP action correlates with tissue Aβ levels. Consistent with Aβ-mediated activity, the increased antimicrobial action was ablated by immunodepletion of AD brain homogenates with anti-Aβ antibodies. Conclusions/Significance Our findings suggest Aβ is a hitherto unrecognized AMP that may normally function in the innate immune system. This finding stands in stark contrast to current models of Aβ-mediated pathology and has important implications for ongoing and future AD treatment strategies. PMID:20209079

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

PubMed

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

2016-01-01

Bacterial resistance to conventional antibiotics is a global threat that has spurred the development of antimicrobial peptides (AMPs) and their mimetics as novel anti-infective agents. While the bioavailability of AMPs is often reduced due to protease activity, the non-natural structure of AMP mimetics renders them robust to proteolytic degradation, thus offering a distinct advantage for their clinical application. We explore the therapeutic potential of N-substituted glycines, or peptoids, as AMP mimics using a multi-faceted approach that includes in silico, in vitro, and in vivo techniques. We report a new QSAR model that we developed based on 27 diverse peptoid sequences, which accurately correlates antimicrobial peptoid structure with antimicrobial activity. We have identified a number of peptoids that have potent, broad-spectrum in vitro activity against multi-drug resistant bacterial strains. Lastly, using a murine model of invasive S. aureus infection, we demonstrate that one of the best candidate peptoids at 4 mg/kg significantly reduces with a two-log order the bacterial counts compared with saline-treated controls. Taken together, our results demonstrate the promising therapeutic potential of peptoids as antimicrobial agents.

Preparation of SiO2@Ag Composite Nanoparticles and Their Antimicrobial Activity.

PubMed

Qin, Rui; Li, Guian; Pan, Liping; Han, Qingyan; Sun, Yan; He, Qiao

2017-04-01

At normal atmospheric temperature, the modified sol–gel method was employed to synthesize SiO2 nanospheres (SiO2 NSs) whose average size was about 352 nm. Silver nanoparticles (Ag NPs) were uniformly distributed on the surface of SiO2 nanospheres (SiO2 NSs) by applying chemical reduction method at 95 °C and the size of silver nanoparticles (Ag NPs) could be controlled by simply tuning the reaction time and the concentration of sodium citrate. Besides, the size, morphology, structure and optical absorption properties of SiO2@Ag composite nanoparticles were measured and characterized by laser particle size analyzer (LPSA), transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD) and ultraviolet visible absorption spectrometer (UV-Vis), respectively. Furthermore, antimicrobial effect experiments that against gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureus) were carried out to characterize the antibacterial activity of synthesized SiO2@Ag composite nanoparticles. The results show that the prepared SiO2@Ag composite nanoparticles have strong antimicrobial activity, which is associated with the size of silver nanoparticles.

Synthesis of fluorine substituted hydroxyapatite nanopowders and application of the central composite design for determination of its antimicrobial effects

NASA Astrophysics Data System (ADS)

Stanić, Vojislav; Dimitrijević, Suzana; Antonović, Dušan G.; Jokić, Bojan M.; Zec, Slavica P.; Tanasković, Sladjana T.; Raičević, Slavica

2014-01-01

Synthetic biomaterials based on fluorine substituted hydroxyapatite are potentially attractive for orthopedic and dental implant applications. The new synthesis of fluorine substituted hydroxyapatite samples were done by neutralization, which consists of adding the solution of HF and H3PO4 in suspension of Ca(OH)2. Characterization studies from XRD, SEM and FTIR spectra showed that crystals are obtained with apatite structure and those particles of all samples are nano size, with an average length of 80 nm and about 15-25 nm in diameter. The central composite design was used in order to determine the optimal conditions for the antimicrobial activity of the synthesized samples. In order to evaluate the influence of operating parameters on the percent of viable cell reduction of Streptococcus mutans, three independent variables were chosen: exposure time, pH of saline and floride concentration in apatite samples. The experimental and predicted antimicrobial activities were in close agreement. Antimicrobial activity of the samples increases with the increase of fluoride concentration and the decreased pH of saline. The maximum antimicrobial activity was achieved at the initial pH of 4.

Anion effects on anti-microbial activity of poly[1-vinyl-3-(2-sulfoethyl imidazolium betaine)].

PubMed

Garg, Godawari; Chauhan, Ghanshyam S; Gupta, Reena; Ahn, J-H

2010-04-01

Recent investigations in the anti-microbial properties of the functional polymers are predominantly focused on the structure of the cationic moieties. In the present study, we investigated that the nature of the anion present in polysulfobetaines affects activity against certain microorganisms and their anti-microbial properties have been rationalized in terms of the structure-activity relationship. Vinyl imidazolium-based polysulfobetaines were prepared by the quaternization of poly(N-vinyl imidazole) with sodium salt of 2-bromo ethanesulfonic acid. The bromide counter anion of the resulting polymer was exchanged with different anions to generate a series of polymers. These were characterized by FTIR, DSC, XRD, SEM, elemental analysis (C, H, N and S) and viscosity measurements. The anti-microbial activity studies were carried against three fungi (Aspergillus niger, Byssochlamys fulva and Mucor circenelliods) and two bacteria (Bacillus coagulans BTS-3 and Pseudomonas aeruginosa BTS-2). The nature of the anion affects the structure of polysulfobetaine by realignment of polymer chains. The anion-dependent anti-microbial properties of polysulfobetaines result from the interaction of the microbes at the polymer interface. Copyright 2009 Elsevier Inc. All rights reserved.

Biochemical Characterization and Antimicrobial and Antifungal Activity of Two Endemic Varieties of Garlic (Allium sativum L.) of the Campania Region, Southern Italy.

PubMed

Fratianni, Florinda; Riccardi, Riccardo; Spigno, Patrizia; Ombra, Maria Neve; Cozzolino, Autilia; Tremonte, Patrizio; Coppola, Raffaele; Nazzaro, Filomena

2016-07-01

Extracts of the bulbs of the two endemic varieties "Rosato" and "Caposele" of Allium sativum of the Campania region, Southern Italy, were analyzed. The phenolic content, ascorbic acid, allicin content, and in vitro antimicrobial and antifungal activity were determined. Ultra performance liquid chromatography with diode array detector performed polyphenol profile. The polyphenolic extracts showed antioxidant activity (EC50) lower than 120 mg. The amount of ascorbic acid and allicin in the two extracts was similar. Polyphenol extract exhibited antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and (only by the extract of Rosato) against Bacillus cereus. The extract of Caposele was more effective in inhibiting the growth of Aspergillus versicolor and Penicillum citrinum. On the other hand, the extract of Rosato was effective against Penicillium expansum.

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

NASA Astrophysics Data System (ADS)

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).

Synthesis, characterisaion and antimicrobial activity of polypropylenamine metallodendrimers modified with 1,8-naphthalimides

NASA Astrophysics Data System (ADS)

Staneva, Desislava; Grabchev, Ivo; Bosch, Paula; Vasileva-Tonkova, Evgenia; Kukeva, Rositsa; Stoyanova, Radostina

2018-07-01

Two novel metal complexes of modified with 1,8-naphthalimide poly(propylenamine) dendrimer of first generation have been synthesized and characterized. By different analytical methods it was shown that the complex composition includes one ligand and one metal ion. The antimicrobial activity of the dendrimer and metallodendrimers was investigated in vitro against different Gram-positive and Gram-negative bacteria and yeasts. The antibacterial effect of thin polylactide film impregnated with the new compounds was also evaluated.

Antimalarial, antimicrobial, cytotoxic, DNA interaction and SOD like activities of tetrahedral copper(II) complexes

NASA Astrophysics Data System (ADS)

Mehta, Jugal V.; Gajera, Sanjay B.; Patel, Mohan N.

2015-02-01

The mononuclear copper(II) complexes with P, O-donor ligand and different fluoroquinolones have been synthesized and characterized by elemental analysis, electronic spectra, TGA, EPR, FT-IR and LC-MS spectroscopy. An antimicrobial efficiency of the complexes has been tested against five different microorganisms in terms of minimum inhibitory concentration (MIC) and displays very good antimicrobial activity. The binding strength and binding mode of the complexes with Herring Sperm DNA (HS DNA) have been investigated by absorption titration and viscosity measurement studies. The studies suggest the classical intercalative mode of DNA binding. Gel electrophoresis assay determines the ability of the complexes to cleave the supercoiled form of pUC19 DNA. Synthesized complexes have been tested for their SOD mimic activity using nonenzymatic NBT/NADH/PMS system and found to have good antioxidant activity. All the complexes show good cytotoxic and in vitro antimalarial activities.

Synthesis, characterization and anti-microbial activity of phenylurea-formaldehyde resin (PUF) and its polymer metal complexes (PUF-Mn(II)

NASA Astrophysics Data System (ADS)

Ahamad, Tansir; Alshehri, Saad M.

2012-10-01

Phenylurea-formaldehyde polymer (PUF) was synthesized via polycondensation of phenylurea and formaldehyde in basic medium, its polymer-metal complexes [PUF-M(II)] were prepared with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) ions. PUF and PUF-M(II) were characterized with magnetic moment measurements, elemental and spectral (UV-visible, FTIR, 1H-NMR, 13C-NMR and ESR) analysis. The thermal behaviors of all the synthesized polymers were carried out using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The thermal data revealed that all of the PUF-M(II) showed higher thermal stabilities than the PUF and also ascribed that the PUF-Cu(II) showed better thermal stability than the other PUF-M(II). The kinetic parameters such as activation energy, pre-exponential factor etc., were evaluated for these polymer metal complexes using Coats-Redfern equation. In addition, the antimicrobial activity of the synthesized polymers was tested against several microorganisms using agar well diffusion methods. Among all of the PUF-M(II), the antimicrobial activity of the PUF-Cu(II) showed the highest zone of inhibition because of its higher stability constant and may be used in biomedical applications.

Preparation of antimicrobial MnO4--doped nylon-66 fibers with excellent laundering durability

NASA Astrophysics Data System (ADS)

Zhang, Mingxing; Gao, Qianhong; Yang, Chenguang; Pang, Lijuan; Wang, Honglong; Li, Rong; Xing, Zhe; Hu, Jiangtao; Wu, Guozhong

2017-11-01

A highly effective antimicrobial nylon 66 fiber doped with permanganate ions was prepared via a simultaneous irradiation induced graft polymerization. The physicochemical properties of the fibers were carefully characterized by various techniques, including Fourier-transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy, revealing that permanganate ions (about 1.48 mmol/g) have been successfully loaded onto the surface of the nylon 66 fibers. The antimicrobial activity of the modified nylon 66 fibers against Staphylococcus aureus and Candida albicans were investigated. Accelerated laundering tests and tensile tests were conducted to access the effect of laundering on the antimicrobial activity and the mechanical property of the modified nylon 66 fibers, respectively. All results indicate that we have prepared a new highly effective antimicrobial nylon 66 fiber (almost a 100% reduction in the number of S. aureus and C. albicans colonies). Furthermore, the modified nylon 66 fibers are durable, maintaining antimicrobial resistance after 100 commercial or domestic launderings and retaining its excellent mechanical property during preparation and laundering.

Antimicrobial and anticancer potential of low molecular weight polypeptides extracted and characterized from leaves of Azadirachta indica.

PubMed

Al Saiqali, Mohammed; Tangutur, Anjana Devi; Banoth, Chandrasekhar; Bhukya, Bhima

2018-07-15

Low molecular weight antimicrobial polypeptides were extracted and purified from the young fresh leaves of Azadirachta indica (neem). The total protein extracted was precipitated with 15% TCA-Acetone. The total purified proteins yielded from the two extraction methods were 122.33±2.21 and 115.09±1.88mg/g of the total fresh weight. The SDS-PAGE analysis identified the presence of eight low molecular weight polypeptide bands. The antimicrobial activity of the resolved bands was detected by Polyacrylamide gel-Agar overlay diffusion assay (PAG-ADA). Their broad-spectrum bactericidal activity was confirmed using the same technique and found three low molecular weight bands from 11 to 14kDa collectively exhibiting superior bactericidal activities against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermis, Enterococcus faecalis, Pseudomonas aeruginosa and fungicidal activity against Candida tropicalis. The FTIR spectrum of the protein bands depicted the presence of hydroxyl and carbonyl groups in the protein bands. These polypeptides were characterized by MALDI-TOF/TOF analysis. Further, the purified protein extract was found to be active against HELA, BT-549 and Neuro-2a cell lines with IC 50 value of 74.03±2.31, 64.82±1.64, 238.32±2.12 and 109.94±2.96, 59.61±0.75 for 24h and 48h, respectively. The results of present study indicate that these polypeptides exhibit broad spectrum antimicrobial and anticancer activity and can therefore be explored for their therapeutic potential. Copyright © 2018 Elsevier B.V. All rights reserved.

Bioinspired green synthesis of copper oxide nanoparticles from Syzygium alternifolium (Wt.) Walp: characterization and evaluation of its synergistic antimicrobial and anticancer activity

NASA Astrophysics Data System (ADS)

Yugandhar, Pulicherla; Vasavi, Thirumalanadhuni; Uma Maheswari Devi, Palempalli; Savithramma, Nataru

2017-10-01

In recent times, nanoparticles are attributed to green nanotechnology methods to know the synergistic biological activities. To accomplish this phenomenon, present study was aimed to synthesize copper oxide nanoparticles (CuO NPs) by using Syzygium alternifolium stem bark, characterized those NPs using expository tools and to elucidate high prioritized antimicrobial and anticancer activities. Synthesized particles exhibited a color change pattern upon synthesis and affirmed its respective broad peak at 285 nm which was analyzed through UV-vis spectroscopy. FT-IR study confirmed that phenols and primary amines were mainly involved in capping and stabilization of nanoparticles. DLS and Zeta potential studies revealed narrow size of particles with greater stability. XRD studies revealed the crystallographic nature of particles with 17.2 nm average size. Microscopic analysis by using TEM revealed that particle size range from 5-13 nm and most of them were spherical in shape, non-agglomerated and poly-dispersed in condition. Antimicrobial studies of particles showed highest inhibitory activity against E. coli and T. harzianum among bacterial and fungal strains, respectively. The scope of this study is extended by examining anticancer activity of CuO NPs. This study exhibited potential anticancer activity towards MDA-MB-231 human breast cancer lines. Overall, these examinations relate that the S. alternifolium is described as efficient well-being plant and probabilistically for the design and synthesis of nanoparticles for human health. This study paves a way to better understand antimicrobial and anticancer therapeutic drug potentials of nanoparticles to design and analysis of pharmaceuticals by in vivo and in vitro approaches.

Electrospun antimicrobial hybrid mats: Innovative packaging material for meat and meat-products.

PubMed

Amna, Touseef; Yang, Jieun; Ryu, Kyeong-Seon; Hwang, I H

2015-07-01

To prevent the development and spread of spoilage/pathogenic microorganisms via meat foodstuffs, antimicrobial nanocomposite packaging can serve as a potential alternative. The objective of this study was to develop a new class of antimicrobial hybrid packaging mat composed of biodegradable polyurethane supplemented with virgin olive oil and zinc oxide via electrospinning. Instead of mixing antimicrobial compounds directly with food, incorporation in packaging materials allows the functional effect at food surfaces where microbial activity is localized. The nanofibers were characterized by SEM, EDX, XRD and TEM. The antibacterial activity was tested against two common foodborne pathogens viz., Staphylococcus aureus and Salmonella typhimurium. The present results indicated that incorporation of olive oil in the polymer affected morphology of PU nanofibers and nanocomposite packaging were able to inhibit growth of pathogens. Thus; as-spun mat can be used as prospective antimicrobial packaging, which potentially reduces contamination of meat/meat-products. Moreover, introduced biodegradable packaging for meat products could serve to replace PVC films and simultaneously help to protect natural environment.

Mathermycin, a Lantibiotic from the Marine Actinomycete Marinactinospora thermotolerans SCSIO 00652.

PubMed

Chen, Erquan; Chen, Qi; Chen, Shaoming; Xu, Bing; Ju, Jianhua; Wang, Huan

2017-08-01

Lantibiotics are antimicrobial peptides belonging to the family of ribosomally synthesized and posttranslationally modified peptides (RiPPs) and feature thioether linkages in their structures. In this study, we identified the biosynthetic gene cluster of a cinnamycin analog, named mathermycin, from Marinactinospora thermotolerans SCSIO 00652 and reconstituted its biosynthesis in Streptomyces lividans and Escherichia coli Key posttranslational modification enzymes of mathermycin were characterized. Mathermycin exhibited antimicrobial activity and therefore represents an example of cinnamycin-like lantibiotics from Marinactinospora species. IMPORTANCE The discovery of new antimicrobial compounds that can be used as potential drugs is in urgent need due to increasing bacterial resistance to current antibiotics. Lantibiotics are important antimicrobial compounds that have found applications in both the clinic setting and food industry. We report here the discovery of a new lantibiotic, mathermycin, from a marine-derived Marinactinospora thermotolerans strain and elucidation of its biosynthesis. We also demonstrate that mathermycin possesses antimicrobial activity toward a Bacillus strain. Copyright © 2017 American Society for Microbiology.

Isolation and characterization of Bacillus sp. GFP-2, a novel Bacillus strain with antimicrobial activities, from Whitespotted bamboo shark intestine.

PubMed

Wu, Jia; Xu, Guoqiang; Jin, Yangyang; Sun, Cong; Zhou, Li; Lin, Guodong; Xu, Rong; Wei, Ling; Fei, Hui; Wang, Dan; Chen, Jianqing; Lv, Zhengbing; Liu, Kuancheng

2018-05-22

The abuse of antibiotics and following rapidly increasing of antibiotic-resistant pathogens is the serious threat to our society. Natural products from microorganism are regarded as the important substitution antimicrobial agents of antibiotics. We isolated a new strain, Bacillus sp. GFP-2, from the Chiloscyllium plagiosum (Whitespotted bamboo shark) intestine, which showed great inhibitory effects on the growth of both Gram-positive and Gram-negative bacteria. Additionally, the growth of salmon was effectively promoted when fed with inactivated strain GFP-2 as the inhibition agent of pathogenic bacteria. The genes encoding antimicrobial peptides like LCI, YFGAP and hGAPDH and gene clusters for secondary metabolites and bacteriocins, such as difficidin, bacillibactin, bacilysin, surfactin, butirosin, macrolactin, bacillaene, fengycin, lanthipeptides and LCI, were predicted in the genome of Bacillus sp. GFP-2, which might be expressed and contribute to the antimicrobial activities of this strain. The gene encoding β-1,3-1,4-glucanase was successfully cloned from the genome and this protein was detected in the culture supernatant of Bacillus sp. GFP-2 by the antibody produced in rabbit immunized with the recombinant β-1,3-1,4-glucanase, indicating that this strain could express β-1,3-1,4-glucanase, which might partially contribute to its antimicrobial activities. This study can enhance a better understanding of the mechanism of antimicrobial activities in genus Bacillus and provide a useful material for the biotechnology study in antimicrobial agent development.

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

PubMed

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

2014-12-01

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

Synthesis and characterization of nano-encapsulated black pepper oleoresin using hydroxypropyl beta-cyclodextrin for antioxidant and antimicrobial applications.

PubMed

Teixeira, Bruna N; Ozdemir, Necla; Hill, Laura E; Gomes, Carmen L

2013-12-01

Previous studies have reported antimicrobial and antioxidant activity of black pepper oleoresin which is associated to its phenolic compounds and piperine. The ability of cyclodextrins to form an inclusion complex with a guest molecule could improve black pepper oleoresin application, bioavailability, and stability in foods. Hydroxypropyl beta-cyclodextrin (HPBCD) inclusion complex with black pepper olereosin were synthesized using the kneading method and characterized for its physico-chemical properties and its antioxidant and antimicrobial activities. Inclusion complex size was 103.9 ± 7.6 nm and indicated to be a polydisperse system. The entrapment efficiency was 78.3 ± 3.6%, which suggests that other constituents in black pepper oleoresin have higher affinities for HPBCD than piperine (major compound in black pepper oleoresin). Thermograms showed the disappearance of oxidation peaks of black pepper oleoresin, proving complex formation with HPBCD. Phase solubility results indicated 1:1 stoichiometric inclusion complex formation and an increase of black pepper oleoresin aqueous solubility with HPBCD concentration. Nano-encapsulation with HPBCD did not affect (P > 0.05) total phenolic content; however, it enhanced (P < 0.05) black pepper oleoresin antioxidant activity. Black pepper oleoresin and its inclusion complex were analyzed for their antimicrobial activity against Escherichia coli K12 and Salmonella enterica serovar Typhimurium LT2. Both free and encapsulated black pepper oleoresin effectively inhibited bacterial growth within the concentration range tested. Black pepper oleoresin encapsulated in HPBCD was able to inhibit Salmonella at lower (P < 0.05) concentrations than its corresponding free extract. Therefore, black pepper oleoresin-HPBCD nanocapsules could have important applications in the food industry as antimicrobial and antioxidant system. © 2013 Institute of Food Technologists®

Antimicrobial activity of silver nanoparticles synthesized using honey and gamma radiation against silver-resistant bacteria from wounds and burns

NASA Astrophysics Data System (ADS)

Hosny, A. M. S.; Kashef, M. T.; Rasmy, S. A.; Aboul-Magd, D. S.; El-Bazza, Z. E.

2017-12-01

Silver nanoparticles (AgNPs) are promising antimicrobial agents for treatment of wounds and burns. We synthesized AgNPs using honey at different pH values or with different gamma irradiation doses. The resulting nanoparticles were characterized by UV-vis spectroscopy, TEM, DLS and FTIR. Their antimicrobial activity, against standard bacterial strains and silver-resistant clinical isolates from infected wounds and burns, was evaluated in vitro through determination of their minimum inhibitory concentration (MIC). AgNPs prepared using 30 g of honey exposed to 5 kGy gamma radiation had the best physical characters regarding stability and uniformity of particle size and shape. They recorded the lowest MIC values against both the standard and silver-resistant isolates. In conclusion, honey and gamma radiation can be used in synthesis of highly stable pure AgNPs, without affecting the physico-chemical and antimicrobial activity of honey. This offered an advantage in terms of inhibition of silver-resistant bacteria isolates.

Preparation, Characterization, and Antimicrobial Activities of Bimetallic Complexes of Sarcosine with Zn(II) and Sn(IV)

PubMed Central

Arafat, Yasir; Ali, Saqib; Shahzadi, Saira; Shahid, Muhammad

2013-01-01

Heterobimetallic complexes of Zn(II) and Sn(IV) with sarcosine have been synthesized at room temperature under stirring conditions by the reaction of sarcosine and zinc acetate in 2 : 1 molar ratio followed by the stepwise addition of CS2 and organotin(IV) halides, where R = Me, n-Bu, and Ph. The complexes were characterized by elemental analysis, FT-IR and NMR (1H, 13C) spectroscopy. IR data showed that the ligand acts in a bidentate manner. NMR data revealed the four coordinate geometry in solution state. In vitro antimicrobial activities data showed that complexes (3) and (4) were effective against bacterial and fungal strains with few exceptions. PMID:24235910

Synthesis, characterization and antimicrobial evaluation of some new schiff, mannich and acetylenic Mannich bases incorporating a 1,2,4-triazole nucleus.

PubMed

Aouad, Mohamed R

2014-11-18

A series of Schiff and Mannich bases derived from 4-amino-5-(3-fluoro-phenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione were synthesized. The alkylation of 4-phenyl-5-(3-fluorophenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione with propargyl bromide afforded the corresponding thiopropargylated derivative which upon treatment with the appropriate secondary amines in the presence of CuCl2 furnished the desired acetylenic Mannich bases. The synthesized compounds were characterized on the basis of their spectral (IR, 1H- and 13C-NMR) data and evaluated for their biological activities. Some of the compounds were found to exhibit significant antimicrobial activity.

Nanovesicle encapsulation of antimicrobial peptide P34: physicochemical characterization and mode of action on Listeria monocytogenes

NASA Astrophysics Data System (ADS)

da Silva Malheiros, Patrícia; Sant'Anna, Voltaire; Micheletto, Yasmine Miguel Serafini; da Silveira, Nadya Pesce; Brandelli, Adriano

2011-08-01

Antimicrobial peptide P34, a substance showing antibacterial activity against pathogenic and food spoilage bacteria, was encapsulated in liposomes prepared from partially purified soybean phosphatidylcholine, and their physicochemical characteristics were evaluated. The antimicrobial activity was estimated by agar diffusion assay using Listeria monocytogenes ATCC 7644 as indicator strain. A concentration of 3,200 AU/mL of P34 was encapsulated in nanovesicles and stocked at 4 °C. No significant difference ( p > 0.05) in the biological activity of free and encapsulated P34 was observed through 24 days. Size and PDI of liposomes, investigated by light scattering analysis, were on average 150 nm and 0.22 respectively. Zeta potential was -27.42 mV. There was no significant change ( p > 0.05) in the physicochemical properties of liposomes during the time of evaluation. The liposomes presented closed spherical morphology as visualized by transmission electron microscopy (TEM). The mode of action of liposome-encapsulated P34 under L. monocytogenes cells was investigated by TEM. Liposomes appeared to adhere but not fuse with the bacterial cell wall, suggesting that the antimicrobial is released from nanovesicles to act against the microorganism. The effect of free and encapsulated P34 was tested against L. monocytogenes, showing that free bacteriocin inhibited the pathogen more quickly than the encapsulated P34. Liposomes prepared with low-cost lipid showed high encapsulation efficiency for a new antimicrobial peptide and were stable during storage. The mode of action against the pathogen L. monocytogenes was characterized.

Fabrication, characterization and in vitro evaluation of silibinin nanoparticles: an attempt to enhance its oral bioavailability

PubMed Central

Sahibzada, Muhammad Umar Khayam; Sadiq, Abdul; Khan, Shahzeb; Faidah, Hani S; Naseemullah; Khurram, Muhammad; Amin, Muhammad Usman; Haseeb, Abdul

2017-01-01

Background Silibinin has gained in importance in the past few decades as a hepatoprotector and is used widely as oral therapy for toxic liver damage, liver cirrhosis, and chronic inflammatory liver diseases, as well as for the treatment of different types of cancers. Unfortunately, it has low aqueous solubility and inadequate dissolution, which results in low oral bioavailability. Materials and methods In this study, nanoparticles (NPs) of silibinin, which is a hydrophobic drug, were manufactured using two cost-effective methods. Antisolvent precipitation with a syringe pump (APSP) and evaporative precipitation of nanosuspension (EPN) were used. The prepared NPs were characterized using different analytical techniques such as scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray powder diffractometry (XRD) and were sifted for their bioavailability through in vitro dissolution and solubility studies. Moreover, the prepared NPs were evaluated for antimicrobial activity against a battery of bacteria and yeast. Results DSC and XRD studies indicated that the prepared NPs were amorphous in nature, with more solubility and dissolution compared to the crystalline form of this drug. NPs prepared through the EPN method had better results than those prepared using the APSP method. Antimicrobial activities of the NPs were improved compared to the unprocessed drugs, while having comparable activities to standard antimicrobial drugs. Conclusion Results indicate that the NPs have significantly increased solubility, dissolution rate, and antimicrobial activities due to the conversion of crystalline structure into amorphous form. PMID:28553075

Breast Cancer Stem Cells in Antiestrogen Resistance

DTIC Science & Technology

2014-10-01

immunogen.Theproduced antibodywas purifiedwith an affinity columnmade of immuno- gen peptides . The antibodywas characterized and validatedwith a number of...et al., 2003), PTP1B enzyme inhibitory (Chen et al., 2002; Nguyen et al., 2012), antimicrobial , cytotoxic (Sohn et al., 2004), antiplatelet (Lin et al...C.S., Kang, S.S., 2004. Antimicrobial and cytotoxic activity of 18 prenylated flavonoids isolated frommedicinal plants:Morus alba L., Morusm ongolica

Probing Protein Sequences as Sources for Encrypted Antimicrobial Peptides

PubMed Central

Brand, Guilherme D.; Magalhães, Mariana T. Q.; Tinoco, Maria L. P.; Aragão, Francisco J. L.; Nicoli, Jacques; Kelly, Sharon M.; Cooper, Alan; Bloch, Carlos

2012-01-01

Starting from the premise that a wealth of potentially biologically active peptides may lurk within proteins, we describe here a methodology to identify putative antimicrobial peptides encrypted in protein sequences. Candidate peptides were identified using a new screening procedure based on physicochemical criteria to reveal matching peptides within protein databases. Fifteen such peptides, along with a range of natural antimicrobial peptides, were examined using DSC and CD to characterize their interaction with phospholipid membranes. Principal component analysis of DSC data shows that the investigated peptides group according to their effects on the main phase transition of phospholipid vesicles, and that these effects correlate both to antimicrobial activity and to the changes in peptide secondary structure. Consequently, we have been able to identify novel antimicrobial peptides from larger proteins not hitherto associated with such activity, mimicking endogenous and/or exogenous microorganism enzymatic processing of parent proteins to smaller bioactive molecules. A biotechnological application for this methodology is explored. Soybean (Glycine max) plants, transformed to include a putative antimicrobial protein fragment encoded in its own genome were tested for tolerance against Phakopsora pachyrhizi, the causative agent of the Asian soybean rust. This procedure may represent an inventive alternative to the transgenic technology, since the genetic material to be used belongs to the host organism and not to exogenous sources. PMID:23029273

Synthesis and Evaluation of Ester Derivatives of 10-Hydroxycanthin-6-one as Potential Antimicrobial Agents.

PubMed

Zhao, Fei; Dai, Jiang-Kun; Liu, Dan; Wang, Shi-Jun; Wang, Jun-Ru

2016-03-21

As part of our continuing research on canthin-6-one antimicrobial agents, a new series of ester derivatives of 10-hydroxycanthin-6-one were synthesized using a simple and effective synthetic route. The structure of each compound was characterized by NMR, ESI-MS, FT-IR, UV, and elemental analysis. The antimicrobial activity of these compounds against three phytopathogenic fungi (Alternaria solani, Fusarium graminearum, and Fusarium solani) and four bacteria (Bacillus cereus, Bacillus subtilis, Ralstonia solanacearum, and Pseudomonas syringae) were evaluated using the mycelium linear growth rate method and micro-broth dilution method, respectively. The structure-activity relationship is discussed. Of the tested compounds, 4 and 7s displayed significant antifungal activity against F. graminearum, with inhibition rates of 100% at a concentration of 50 μg/mL. Compounds 5, 7s, and 7t showed the best inhibitory activity against all the tested bacteria, with minimum inhibitory concentrations (MICs) between 3.91 and 31.25 μg/mL. Thus, 7s emerged as a promising lead compound for the development of novel canthine-6-one antimicrobial agents.

Effect of glycerol and zinc oxide addition on antibacterial activity of biodegradable bioplastics from chitosan-kepok banana peel starch

NASA Astrophysics Data System (ADS)

Agustin, Y. E.; Padmawijaya, K. S.

2017-07-01

Bioplastic is a biopolymer plastic that can be degraded easily by microorganisms so it can be used as alternative replaced commercial plastic. This research aims to study the effects of additive (glycerol and zinc oxide) addition in the characteristic of antimicrobial activity and biodegradability bioplastic from chitosan and Kepok banana peel starch. In this research, bioplastics were synthesized by chitosan as the backbone and antimicrobial, Kepok banana peel starch as filler, glycerol as plasticizer, also ZnO as an amplifier. Bioplastics were characterized their antimicrobial activity using agar diffusion method (zone inhibition assay) and biodegradability test using microbe (EM4). The result showed the optimum composition of bioplastic is kitosan 4 - 30% starch - 5 mL glycerol - 5% ZnO gives the good antimicrobial activity towards gram positive and gram negative bacteria, and this bioplastic will be degraded within an hour and 12 min. Thus, this bioplastics may have potential to be use for food packaging by having biodegradable properties and also inhibit bacterial growth.

Discovery and Biochemical Characterization of PlyP56, PlyN74, and PlyTB40—Bacillus Specific Endolysins

PubMed Central

Etobayeva, Irina; Linden, Sara B.; Alem, Farhang; Rizkalla, Lucas; Temple, Louise; Hakami, Ramin M.

2018-01-01

Three Bacillus bacteriophage-derived endolysins, designated PlyP56, PlyN74, and PlyTB40, were identified, cloned, purified, and characterized for their antimicrobial properties. Sequence alignment reveals these endolysins have an N-terminal enzymatically active domain (EAD) linked to a C-terminal cell wall binding domain (CBD). PlyP56 has a Peptidase_M15_4/VanY superfamily EAD with a conserved metal binding motif and displays biological dependence on divalent ions for activity. In contrast, PlyN74 and PlyTB40 have T7 lysozyme-type Amidase_2 and carboxypeptidase T-type Amidase_3 EADs, respectively, which are members of the MurNAc-LAA superfamily, but are not homologs and thus do not have a shared protein fold. All three endolysins contain similar SH3-family CBDs. Although minor host range differences were noted, all three endolysins show relatively broad antimicrobial activity against members of the Bacillus cereus sensu lato group with the highest lytic activity against B. cereus ATCC 4342. Characterization studies determined the optimal lytic activity for these enzymes was at physiological pH (pH 7.0–8.0), over a broad temperature range (4–55 °C), and at low concentrations of NaCl (<50 mM). Direct comparison of lytic activity shows the PlyP56 enzyme to be twice as effective at lysing the cell wall peptidoglycan as PlyN74 or PlyTB40, suggesting PlyP56 is a good candidate for further antimicrobial development as well as bioengineering studies. PMID:29883383

Identification and Characterization of the First Cathelicidin from Sea Snakes with Potent Antimicrobial and Anti-inflammatory Activity and Special Mechanism*

PubMed Central

Wei, Lin; Gao, Jiuxiang; Zhang, Shumin; Wu, Sijin; Xie, Zeping; Ling, Guiying; Kuang, Yi-Qun; Yang, Yongliang; Yu, Haining; Wang, Yipeng

2015-01-01

Cathelicidins are a family of gene-encoded peptide effectors of innate immunity found exclusively in vertebrates. They play pivotal roles in host immune defense against microbial invasions. Dozens of cathelicidins have been identified from several vertebrate species. However, no cathelicidin from marine reptiles has been characterized previously. Here we report the identification and characterization of a novel cathelicidin (Hc-CATH) from the sea snake Hydrophis cyanocinctus. Hc-CATH is composed of 30 amino acids, and the sequence is KFFKRLLKSVRRAVKKFRKKPRLIGLSTLL. Circular dichroism spectroscopy and structure modeling analysis indicated that Hc-CATH mainly assumes an amphipathic α-helical conformation in bacterial membrane-mimetic solutions. It possesses potent broad-spectrum and rapid antimicrobial activity. Meanwhile, it is highly stable and shows low cytotoxicity toward mammalian cells. The microbial killing activity of Hc-CATH is executed through the disruption of cell membrane and lysis of bacterial cells. In addition, Hc-CATH exhibited potent anti-inflammatory activity by inhibiting the LPS-induced production of nitric oxide (NO) and pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6. Hc-CATH directly binds with LPS to neutralize its toxicity, and it also binds to Toll-like receptor 4 (TLR4/MD2 complex), which therefore inhibits the binding of LPS to TLR4/MD2 complex and the subsequent activation of LPS-induced inflammatory response pathways. Taken together, our study demonstrates that Hc-CATH, the first cathelicidin from sea snake discovered to have both antimicrobial and anti-inflammatory activity, is a potent candidate for the development of peptide antibiotics. PMID:26013823

Application of Asymmetric Flow Field-Flow Fractionation hyphenations for liposome-antimicrobial peptide interaction.

PubMed

Iavicoli, Patrizia; Urbán, Patricia; Bella, Angelo; Ryadnov, Maxim G; Rossi, François; Calzolai, Luigi

2015-11-27

Asymmetric Flow Field-Flow Fractionation (AF4) combined with multidetector analysis form a promising technique in the field of nanoparticle characterization. This system is able to measure the dimensions and physicochemical properties of nanoparticles with unprecedented accuracy and precision. Here, for the first time, this technique is optimized to characterize the interaction between an archetypal antimicrobial peptide and synthetic membranes. By using charged and neutral liposomes it is possible to mimic some of the charge characteristics of biological membranes. The use of AF4 system allows determining, in a single analysis, information regarding the selectivity of the peptides, the quantity of peptides bound to each liposome, the induced change in the size distribution and morphology of the liposomes. The results obtained provide relevant information for the study of structure-activity relationships in the context of membrane-induced antimicrobial action. This information will contribute to the rational design of potent antimicrobial agents in the future. Moreover, the application of this method to other liposome systems is straightforward and would be extremely useful for a comprehensive characterization with regard to size distribution and protein interaction in the nanomedicine field. Copyright © 2015. Published by Elsevier B.V.

Biosurfactants production potential of native strains of Bacillus cereus and their antimicrobial, cytotoxic and antioxidant activities.

PubMed

Basit, Madiha; Rasool, Muhammad Hidayat; Naqvi, Syed Ali Raza; Waseem, Muhammad; Aslam, Bilal

2018-01-01

Present study was designed to evaluate the biosurfactant production potential by native strains of Bacillus cereus as well as determine their antimicrobial and antioxidant activities. The strains isolated from garden soil were characterized as B. cereus MMIC 1, MMIC 2 and MMIC 3. Biosurfactants were extracted as grey white precipitates. Optimum conditions for biosurfactant production were 37°C, the 7th day of incubation, 0.5% NaCl, pH 7.0. Moreover, corn steep liquor was the best carbon source. Biuret test, Thin Layer Chromatography (TLC), agar double diffusion and Fourier Transform Infrared Spectroscopy (FTIR) characterized the biosurfactants as cationic lipopeptides. Biosurfactants exhibited significant antibacterial and antifungal activity against S. aureus, E. coli, P. aeruginosa, K. pneumoniae, A. niger and C. albicans at 30 mg/ml. Moreover, they also possessed antiviral activity against NDV at 10 mg/ml. Cytotoxicity assay in BHK-21 cell lines revealed 63% cell survival at 10 mg/ml of biosurfactants and thus considered as safe. They also showed very good antioxidant activity by ferric-reducing activity and DPPH scavenging activity at 2 mg/ml. Consequently, the study offers an insight for the exploration of new bioactive molecules from the soil. It was concluded that lipopeptide biosurfactants produced from native strains of B. cereus may be recommended as safe antimicrobial, emulsifier and antioxidant agent.

Antimicrobial agent-free hybrid cationic starch/sodium alginate polyelectrolyte films for food packaging materials.

PubMed

Şen, Ferhat; Uzunsoy, İrem; Baştürk, Emre; Kahraman, Memet Vezir

2017-08-15

This study aimed to develop polyelectrolyte structured antimicrobial food packaging materials that do not contain any antimicrobial agents. Cationic starch was synthesized and characterized by FT-IR spectroscopy and 1 H NMR spectroscopy. Its nitrogen content was determined by Kjeldahl method. Polyelectrolyte structured antimicrobial food packaging materials were prepared using starch, cationic starch and sodium alginate. Antimicrobial activity of materials was defined by inhibition zone method (disc diffusion method). Thermal stability of samples was evaluated by TGA and DSC. Hydrophobicity of samples was determined by contact angle measurements. Surface morphology of samples was investigated by SEM. Moreover, gel contents of samples were determined. The obtained results prove that produced food packaging materials have good thermal, antimicrobial and surface properties, and they can be used as food packaging material in many industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antimicrobial Lemongrass Essential Oil-Copper Ferrite Cellulose Acetate Nanocapsules.

PubMed

Liakos, Ioannis L; Abdellatif, Mohamed H; Innocenti, Claudia; Scarpellini, Alice; Carzino, Riccardo; Brunetti, Virgilio; Marras, Sergio; Brescia, Rosaria; Drago, Filippo; Pompa, Pier Paolo

2016-04-20

Cellulose acetate (CA) nanoparticles were combined with two antimicrobial agents, namely lemongrass (LG) essential oil and Cu-ferrite nanoparticles. The preparation method of CA nanocapsules (NCs), with the two antimicrobial agents, was based on the nanoprecipitation method using the solvent/anti-solvent technique. Several physical and chemical analyses were performed to characterize the resulting NCs and to study their formation mechanism. The size of the combined antimicrobial NCs was found to be ca. 220 nm. The presence of Cu-ferrites enhanced the attachment of LG essential oil into the CA matrix. The magnetic properties of the combined construct were weak, due to the shielding of Cu-ferrites from the polymeric matrix, making them available for drug delivery applications where spontaneous magnetization effects should be avoided. The antimicrobial properties of the NCs were significantly enhanced with respect to CA/LG only. This work opens novel routes for the development of organic/inorganic nanoparticles with exceptional antimicrobial activities.

Novel pyrazole derivatives with oxa/thiadiazolyl, pyrazolyl moieties and pyrazolo[4,3-d]-pyrimidine derivatives as potential antimicrobial and anticancer agents.

PubMed

Hafez, Hend N; El-Gazzar, Abdel-Rhman B A; Al-Hussain, Sami A

2016-05-15

A series of [4-amino-3-(4-chlorophenyl)-1H-pyrazol-5-yl](3,5-dimethyl-1H-pyrazol-1-yl)-methanone and 6-amino-3-(4-chlorophenyl)-5-methyl-1,6-dihydro-7H-pyrazolo[4,3-d]-pyrimidin-7-one have been synthesized from ethyl 4-amino-3-(4-chlorophenyl)-pyrazol-5-carboxylate. The newly synthesized compounds were characterized by IR, (1)H NMR, (13)CNMR, Mass spectra and Elemental analysis. The compounds were evaluated for their in vitro antimicrobial and anticancer activity. Among the synthesized compounds, compounds 7a,b and 15 exhibited higher anticancer activity than the doxorubicin as reference drug. Most of the newly synthesized compounds have good to excellent antimicrobial activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Antimicrobial and antitumor activity of platinum and palladium complexes of novel spherical aramides nanoparticles containing flexibilizing linkages: structure-property relationship.

PubMed

Elhusseiny, Amel F; Hassan, Hammed H A M

2013-02-15

Square planar Pd (II) and octahedral Pt (IV) complexes with novel spherical aramides nanoparticles containing flexible linkages ligands have been synthesized and characterized using analytical and spectral techniques. The synthesized complexes have been tested for their antimicrobial activity using Kirby-Bauer disc diffusion method. The antitumor activity has been performed using liver carcinoma (HEPG2), breast carcinoma (MCF7) and colon carcinoma (HCT 116) cell lines. Palladium complexes of polyamides containing sulfones showed the highest potency as antibacterial and antifungal agents. Platinum complexes containing sulfone and ether flexible linkages and chloro groups exhibited high potency as antitumor and antimicrobial agents. The uniform sizes of these nanomaterials could find biological uses such as immune assay and other medical purposes. Copyright © 2012 Elsevier B.V. All rights reserved.

Synthesis, characterization, antimicrobial and enzymatic activity of 4b,9b-dihydroxy-7,8-dihydro-4bH-indeno[1,2-b]benzofuran-9,10(6H,9bH)-dione

NASA Astrophysics Data System (ADS)

Mehdi, Sayed Hasan; Hashim, Rokiah; Ghalib, Raza Murad; Fátima C. Guedes da Silva, M.; Sulaiman, Othman; Rahman, Syed Ziaur; Murugaiyah, Vikneswaran; Marimuthu, Mani Maran

2011-12-01

The crystal structure of the title compound, 4b,9b-dihydroxy-7,8-dihydro-4bH-indeno[1,2-b]benzofuran-9,10(6H,9bH)-dione has been determined by single crystal X-ray diffraction. It crystallizes in the monoclinic space group P2 1/c with Z = 4. The FTIR as well as the 1H and 13C NMR spectra of the compound were also recorded and briefly discussed. The compound showed potential antimicrobial activity comparable to that of clinically used antimicrobial agents against selected microorganisms. It has selective and moderate inhibitory activity on butyryl cholinesterase enzyme and could serve as potential lead compound for synthesis of more bioactive derivatives.

Antimicrobial activity of a 48-kDa protease (AMP48) from Artocarpus heterophyllus latex.

PubMed

Siritapetawee, J; Thammasirirak, S; Samosornsuk, W

2012-01-01

Artocarpus heterophyllus (jackfruit) is a latex producing plant. Plant latex is produced from secretory cells and contains many intergradients. It also has been used in folk medicine. This study aimed to purify and characterize the biological activities of a protease from jackfruit latex. A protease was isolated and purified from crude latex of a jackfruit tree by acid precipitation and ion exchange chromatography. The proteolytic activities of protein were tested using gelatin- and casein-zymography. The molecular weight and isoelectric point (pl) of protein were analysed by SDS/12.5% PAGE and 2D-PAGE, respectively. Antimicrobial activity of protein was analysed by broth microdilution method. In addition, the antibacterial activity of protein against Pseudomonas aeruginosa ATCC 27853 was observed and measured using atomic force microscopy (AFM) technique. The purified protein contained protease activity by digesting gelatin- and casein-substrates. The protease was designated as antimicrobial protease-48 kDa or AMP48 due to its molecular mass on SDS-PAGE was approximately 48 kDa. The isoelectric point (pl) of AMP48 was approximately 4.2. In addition, AMP48 contained antimicrobial activities by it could inhibit the growths of Pseudomonas aeruginosa ATCC 27853 and clinical isolated Candida albicans at minimum inhibitory concentration (MIC) 2.2 mg/ml and Minimum microbicidal concentration (MMC) 8.8 mg/ml. AFM image also supported the antimicrobial activities of AMP48 by the treated bacterial morphology and size were altered from normal.

Use of rosemary, oregano, and a commercial blend of essential oils in broiler chickens: in vitro antimicrobial activities and effects on growth performance.

PubMed

Mathlouthi, N; Bouzaienne, T; Oueslati, I; Recoquillay, F; Hamdi, M; Urdaci, M; Bergaoui, R

2012-03-01

The present study was conducted to characterize the in vitro antimicrobial activities of 3 essential oils [oregano, rosemary, and a commercial blend of essential oils (BEO)] against pathogenic and nonpathogenic bacteria and to evaluate their effects on broiler chicken performances. The chemical composition of the essential oils was determined using the gas chromatography interfaced with a mass spectroscopy. The disc diffusion method, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) were applied for the determination of antimicrobial activities of essential oils. In vivo study, a total of seven hundred fifty 1-d-old male broiler chickens were assigned to 6 dietary treatment groups: basal diet (control; CON), CON + 44 mg of avilamycin/kg (A), CON + 100 mg of rosemary essential oil/kg (ROS), CON + 100 mg of oregano essential oil/kg (OR), CON + 50 mg of rosemary and 50 mg of oregano essential oils/kg (RO), and CON + 1,000 mg of BEO/kg (essential oil mixture, EOM). The essential oils isolated from rosemary and oregano were characterized by their greater content of 1,8-cineole (49.99%) and carvacrol (69.55%), respectively. The BEO was mainly represented by the aldehyde (cinnamaldehyde) and the monoterpene (1,8-cineole) chemical groups. The results of the disc diffusion method indicated that the rosemary essential oil had antibacterial activity (P ≤ 0.05) against only 3 pathogenic bacteria, Escherichia coli (8 mm), Salmonella indiana (11 mm), and Listeria innocua (9 mm). The essential oil of oregano had antimicrobial activities (P ≤ 0.05) on the same bacteria as rosemary but also on Staphylococcus aureus (22 mm) and Bacillus subtilis (12 mm). Oregano essential oil had greater (P ≤ 0.05) antimicrobial activities against pathogenic bacteria than rosemary essential oil but they had no synergism between them. The BEO showed an increased antimicrobial activity (P ≤ 0.05) against all studied bacteria (pathogenic and nonpathogenic bacteria) except for Lactobacillus rhamnosus. The supplementation of the basal diet with avilamycin or essential oils improved (P ≤ 0.05) broiler chicken BW, BW gain, and G:F compared with the CON diet. There were no differences in growth performances among birds fed A, ROS, OR, RO, or EOM diets. In general, essential oils contained in rosemary, oregano, and BEO can substitute for growth promoter antibiotics. Although the 3 essential oils had different antimicrobial activities, they exhibited the same efficiency in broiler chickens.

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

PubMed Central

Fjell, Christopher D.; Waldbrook, Matt; Chongsiriwatana, Nathaniel P.; Yuen, Eddie; Hancock, Robert E. W.; Barron, Annelise E.

2016-01-01

Bacterial resistance to conventional antibiotics is a global threat that has spurred the development of antimicrobial peptides (AMPs) and their mimetics as novel anti-infective agents. While the bioavailability of AMPs is often reduced due to protease activity, the non-natural structure of AMP mimetics renders them robust to proteolytic degradation, thus offering a distinct advantage for their clinical application. We explore the therapeutic potential of N-substituted glycines, or peptoids, as AMP mimics using a multi-faceted approach that includes in silico, in vitro, and in vivo techniques. We report a new QSAR model that we developed based on 27 diverse peptoid sequences, which accurately correlates antimicrobial peptoid structure with antimicrobial activity. We have identified a number of peptoids that have potent, broad-spectrum in vitro activity against multi-drug resistant bacterial strains. Lastly, using a murine model of invasive S. aureus infection, we demonstrate that one of the best candidate peptoids at 4 mg/kg significantly reduces with a two-log order the bacterial counts compared with saline-treated controls. Taken together, our results demonstrate the promising therapeutic potential of peptoids as antimicrobial agents. PMID:26849681

The addition of nanochitosan suspension as filler in carrageenan-tapioca biocomposite film

NASA Astrophysics Data System (ADS)

Rochima, Emma; Fiyanih, Elisah; Afrianto, Eddy; Subhan, Ujang; Praseptiangga, Danar; Panatarani, Camellia; Joni, I. Made

2018-02-01

This research aimed to investigate the effect of nanochitosan (CSNPs) suspension by beads milling method as filler in carrageenan-tapioca biocomposite film. In addition, the antibacterial activity of CSNPs as filler with two food pathogenic bacteria, Staphylococcus aureus and Escherichia coli and then influence of nano fillers for appearance of films were observed. The incorporation of CSNPs suspension with 0.5, 1, 1.5 and 2 (%v/v) in carrageenan-tapioca film exhibited antibacterial activity againts both bacteria. CSNPs had slightly higher antimicrobial activity against E. coli aureus compared to S. aureus at all concentrations due to different mechanisms. Therefore, the best antimicrobial activity was obtained from 1 wt%. Furthermore the best antimicrobial activity was characterized by means of the thickness and transparency. The result showed that the thickness of film was 0.059 mm and the transparency was 87.88. It was concluded that the incorporation of CSNPs suspension 1 wt% in carrageenan-tapioca composite film is suitable for developing active packaging.

Chemical composition, antimicrobial, insecticidal, phytotoxic and antioxidant activities of Mediterranean Pinus brutia and Pinus pinea resin essential oils.

PubMed

Ulukanli, Zeynep; Karabörklü, Salih; Bozok, Fuat; Ates, Burhan; Erdogan, Selim; Cenet, Menderes; Karaaslan, Merve Göksin

2014-12-01

Essential oils of the resins of Pinus brutia and Pinus pinea were evaluated for their biological potential. Essential oils were characterized using GC-MS and GC/FID. in vitro antimicrobial, phytotoxic, antioxidant, and insecticidal activities were carried out using the direct contact and the fumigant assays, respectively. The chemical profile of the essential oils of the resins of P. pinea and P. brutia included mainly α-pinene (21.39% and 25.40%), β-pinene (9.68% and 9.69%), and caryophyllene (9.12% and 4.81%). The essential oils of P. pinea and P. brutia exerted notable antimicrobial activities on Micrococcus luteus and Bacillus subtilis, insecticidal activities on Ephestia kuehniella eggs, phytotoxic activities on Lactuca sativa, Lepidium sativum, and Portulaca oleracea, as well as antioxidant potential. Indications of the biological activities of the essential oils suggest their use in the formulation of ecofriendly and biocompatible pharmaceuticals. Copyright © 2014 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Magnesium Based Materials and their Antimicrobial Activity

NASA Astrophysics Data System (ADS)

Robinson, Duane Allan

The overall goals of this body of work were to characterize the antimicrobial properties of magnesium (Mg) metal and nano-magnesium oxide (nMgO) in vitro, to evaluate the in vitro cytotoxicity of Mg metal, and to incorporate MgO nanoparticles into a polymeric implant coating and evaluate its in vitro antimicrobial properties. In the course of this work it was found that Mg metal, Mg-mesh, and nMgO have in vitro antimicrobial properties that are similar to a bactericidal antibiotic. For Mg metal, the mechanism of this activity appears to be related to an increase in pH (i.e. a more alkaline environment) and not an increase in Mg2+. Given that Mg-mesh is a Mg metal powder, the assumption is that it has the same mechanism of activity as Mg metal. The mechanism of activity for nMgO remains to be elucidated and may be related to a combination of interaction of the nanoparticles with the bacteria and the alkaline pH. It was further demonstrated that supernatants from suspensions of Mg-mesh and nMgO had the same antimicrobial effect as was noted when the particles were used. The supernatant from Mg-mesh and nMgO was also noted to prevent biofilm formation for two Staphylococcus strains. Finally, poly-epsilon-caprolactone (PCL) composites of Mg-mesh (PCL+Mg-mesh) and nMgO (PCL+nMgO) were produced. Coatings applied to screws inhibited growth of Escherichia coli and Pseudomonas aeruginosa and in thin disc format inhibited the growth of Staphylococcus aureus in addition to the E. coli and P. aeruginosa. Pure Mg metal was noted to have some cytotoxic effect on murine fibroblast and osteoblast cell lines, although this effect needs to be characterized further. To address the need for an in vivo model for evaluating implant associated infections, a new closed fracture osteomyelitis model in the femur of the rat was developed. Magnesium, a readily available and inexpensive metal was shown to have antimicrobial properties that appear to be related to its corrosion products and that nMgO has similar effects. Incorporation of nMgO into a PCL composite was easily achieved and revealed similar, although not identical antimicrobial results. This work has provided a strong foundation and methodology for further evaluation of Mg based materials and their antimicrobial properties.

Characterization of an antimicrobial peptide produced by Bacillus subtilis subsp. spizezinii showing inhibitory activity towards Haemophilus parasuis.

PubMed

Teixeira, Mário Lettieri; Dalla Rosa, Andréia; Brandelli, Adriano

2013-05-01

Haemophilus parasuis is the pathogen that causes Glässer's disease, a major illness affecting young pigs. The aim of this work was to investigate the antagonistic activity of antimicrobial substances produced by Bacillus species against H. parasuis. Among the tested strains, only Bacillus subtilis ATCC 6633 inhibited H. parasuis growth. The antibacterial substance was purified by ammonium sulfate precipitation, gel filtration chromatography on Sephadex G-50 and ion-exchange chromatography on DEAE-cellulose. The purification was about 100-fold with a yield of 0.33 %. The purified substance was resistant up to 80 °C and pH ranging 3-7, but the substance lost its activity when it was treated with proteases. The peptide had a molecular mass of 1083 Da and its sequence was determined by MS as NRWCFAGDD, which showed no homology with other known antimicrobial peptides. The complete inhibition of H. parasuis growth was observed at 20 µg peptide ml(-1) after 20 min of exposure. The peptide obtained by chemical synthesis also showed antimicrobial activity on H. parasuis. The identification of antimicrobial substances that can be effective against H. parasuis is very relevant to combat this pathogen that causes important losses in swine production.

Synthesis and In Vitro Antimicrobial Evaluation of New 1,3,4-Oxadiazoles Bearing 5-Chloro-2-methoxyphenyl Moiety.

PubMed

Prasanna Kumar, Basavapatna N; Mohana, Kikkeri N; Mallesha, Lingappa; Harish, Kikkeri P

2013-01-01

A series of new 1,3,4-oxadiazole derivatives, 4(a-h), containing 5-chloro-2-methoxy benzohydrazide moiety were synthesized by the reaction of 5-chloro-2-methoxybenzoate with different aromatic carboxylic acids. These newly synthesized compounds were characterized by FT-IR, (1)H NMR, mass spectra, and also by elemental analysis. All the newly synthesized compounds were screened for their antibacterial and antifungal activities. Antimicrobial studies revealed that compounds 4c, 4f, and 4g showed significant activity against tested strains.

Model Analytical Development for Physical, Chemical, and Biological Characterization of Momordica charantia Vegetable Drug

PubMed Central

Guimarães, Geovani Pereira; Santos, Ravely Lucena; Júnior, Fernando José de Lima Ramos; da Silva, Karla Monik Alves; de Souza, Fabio Santos

2016-01-01

Momordica charantia is a species cultivated throughout the world and widely used in folk medicine, and its medicinal benefits are well documented, especially its pharmacological properties, including antimicrobial activities. Analytical methods have been used to aid in the characterization of compounds derived from plant drug extracts and their products. This paper developed a methodological model to evaluate the integrity of the vegetable drug M. charantia in different particle sizes, using different analytical methods. M. charantia was collected in the semiarid region of Paraíba, Brazil. The herbal medicine raw material derived from the leaves and fruits in different particle sizes was analyzed using thermoanalytical techniques as thermogravimetry (TG) and differential thermal analysis (DTA), pyrolysis coupled to gas chromatography/mass spectrometry (PYR-GC/MS), and nuclear magnetic resonance (1H NMR), in addition to the determination of antimicrobial activity. The different particle surface area among the samples was differentiated by the techniques. DTA and TG were used for assessing thermal and kinetic parameters and PYR-GC/MS was used for degradation products chromatographic identification through the pyrograms. The infusions obtained from the fruit and leaves of Momordica charantia presented antimicrobial activity. PMID:27579215

Investigation of Industrial Polyurethane Foams Modified with Antimicrobial Copper Nanoparticles

PubMed Central

Sportelli, Maria Chiara; Picca, Rosaria Anna; Ronco, Roberto; Bonerba, Elisabetta; Tantillo, Giuseppina; Pollini, Mauro; Sannino, Alessandro; Valentini, Antonio; Cataldi, Tommaso R.I.; Cioffi, Nicola

2016-01-01

Antimicrobial copper nanoparticles (CuNPs) were electrosynthetized and applied to the controlled impregnation of industrial polyurethane foams used as padding in the textile production or as filters for air conditioning systems. CuNP-modified materials were investigated and characterized morphologically and spectroscopically, by means of Transmission Electron Microscopy (TEM), and X-ray Photoelectron Spectroscopy (XPS). The release of copper ions in solution was studied by Electro-Thermal Atomic Absorption Spectroscopy (ETAAS). Finally, the antimicrobial activity of freshly prepared, as well as aged samples—stored for two months—was demonstrated towards different target microorganisms. PMID:28773665

CHARACTERIZATION ADN BIOLOGICAL ACTIVITY OF SECONDARY METABOLITES FROM ARMILLARIA TABESCENS

USDA-ARS?s Scientific Manuscript database

Ethyl acetate extracts from liquid cultures of Armillaria tabescens showed good antimicrobial activity against Candida albicans, Cryptococcus neoformans, Escherichia coli and Mycobacterium intracellulare. Chemical analyses of extract constituents led to the isolation and identification of two new co...

Natural sorbents modified by divalent Cu2+- and Zn2+- ions and their corresponding antimicrobial activity.

PubMed

Đolić, Maja B; Rajaković-Ognjanović, Vladana N; Štrbac, Svetlana B; Dimitrijević, Suzana I; Mitrić, Miodrag N; Onjia, Antonije E; Rajaković, Ljubinka V

2017-10-25

The objective of this study was to investigate the modification of materials used in wastewater treatment for possible antimicrobial application(s). Granulated activated carbon (GAC) and natural clinoptilolite (CLI) were activated using Cu 2+ - and Zn 2+ - ions and the disinfection ability of the resulting materials was tested. Studies of the sorption and desorption kinetics were performed in order to determine and clarify the antimicrobial activity of the metal-activated sorbents. The exact sorption capacities of the selected sorbents, GAC and CLI, activated through use of Cu 2+ - ions, were 15.90 and 3.60mg/g, respectively, while for the materials activated by Zn 2+ - ions, the corresponding capacities were 14.00 and 4.72mg/g,. The desorption rates were 2 and 3 orders of magnitude lower than their sorption efficacy for the Cu 2+ -, and Zn 2+ -activated sorbents, respectively. The intermediate sorption capacity and low desorption rate indicated that the overall antimicrobial activity of the metal-modified sorbents was a result of metal ions immobilized onto surface sites. The effect of antimicrobial activity of free ions desorbed from the metal-activated surface may thus be disregarded. The antimicrobial activities of Cu/GAC, Zn/GAC, Cu/CLI and Zn/CLI were also tested against Escherichia coli, Staphylococcus aureus, and Candida albicans. After 15min exposure, the highest levels of cell inactivation were obtained through the Cu/CLI and the Cu/GAC against E. coli, 100.0 and 98.24%, respectively. However, for S. aureus and yeast cell inactivation, all Cu 2+ - and Zn 2+ -activated sorbents proved to be unsatisfactory. A characterization of the sorbents was performed by X-ray diffraction (XRD), X-ray photo electron spectroscopy (XPS), and field emission scanning electron microscopy (FE-SEM). A concentration of the adsorbed and released ions was determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and mass spectrometry (ICP-MS). The results showed that the antimicrobial performance of the activated sorbents depended on the surface characteristics of the material, which itself designates the distribution and the bioavailability of the activating agent. Copyright © 2017 Elsevier B.V. All rights reserved.

Emergence of Antimicrobial-Resistant Escherichia coli of Animal Origin Spreading in Humans

PubMed Central

Skurnik, David; Clermont, Olivier; Guillard, Thomas; Launay, Adrien; Danilchanka, Olga; Pons, Stéphanie; Diancourt, Laure; Lebreton, François; Kadlec, Kristina; Roux, Damien; Jiang, Deming; Dion, Sara; Aschard, Hugues; Denamur, Maurice; Cywes-Bentley, Colette; Schwarz, Stefan; Tenaillon, Olivier; Andremont, Antoine; Picard, Bertrand; Mekalanos, John; Brisse, Sylvain; Denamur, Erick

2016-01-01

In the context of the great concern about the impact of human activities on the environment, we studied 403 commensal Escherichia coli/Escherichia clade strains isolated from several animal and human populations that have variable contacts to one another. Multilocus sequence typing (MLST) showed a decrease of diversity 1) in strains isolated from animals that had an increasing contact with humans and 2) in all strains that had increased antimicrobial resistance. A specific B1 phylogroup clonal complex (CC87, Institut Pasteur schema nomenclature) of animal origin was identified and characterized as being responsible for the increased antimicrobial resistance prevalence observed in strains from the environments with a high human-mediated antimicrobial pressure. CC87 strains have a high capacity of acquiring and disseminating resistance genes with specific metabolic and genetic determinants as demonstrated by high-throughput sequencing and phenotyping. They are good mouse gut colonizers but are not virulent. Our data confirm the predominant role of human activities in the emergence of antimicrobial resistance in the environmental bacterial strains and unveil a particular E. coli clonal complex of animal origin capable of spreading antimicrobial resistance to other members of microbial communities. PMID:26613786

Evaluation of antimicrobial and anti-inflammatory activities of seed extracts from six Nigella species.

PubMed

Landa, Premysl; Marsik, Petr; Havlik, Jaroslav; Kloucek, Pavel; Vanek, Tomas; Kokoska, Ladislav

2009-04-01

Seed extracts from six species of the genus Nigella (Family Ranunculaceae)-Nigella arvensis, Nigella damascena, Nigella hispanica, Nigella nigellastrum, Nigella orientalis, and Nigella sativa-obtained by successive extraction with n-hexane, chloroform, and methanol, were tested for their antimicrobial activity against 10 strains of pathogenic bacteria and yeast using the microdilution method as well as for anti-inflammatory properties by in vitro cyclooxygenase (COX)-1 and COX-2 assay. Chemical characterization of active extracts was carried out including free and fixed fatty acid analysis. Comparison of antimicrobial activity showed that N. arvensis chloroform extract was the most potent among all species tested, inhibiting Gram-positive bacterial and yeast strains with minimum inhibitory concentration (MIC) values ranging from 0.25 to 1 mg/mL. With the exception of selective inhibitory action of n-hexane extract of N. orientalis on growth of Bacteroides fragilis (MIC = 0.5 mg/mL), we observed no antimicrobial activity for other Nigella species. Anti-inflammatory screening revealed that N. sativa, N. orientalis, N. hispanica, N. arvensis n-hexane, and N. hispanica chloroform extracts had strong inhibitory activity (more than 80%) on COX-1 and N. orientalis, N. arvensis, and N. hispanica n-hexane extracts were most effective against COX-2, when the concentration of extracts was 100 microg/mL in both COX assays. In conclusion, N. arvensis, N. orientalis, and N. hispanica seeds, for the first time examined for antimicrobial and anti-inflammatory effects, revealed their significant activity in one or both assays.

Isolation and identification of antimicrobial compound from Mentha longifolia L. leaves grown wild in Iraq

PubMed Central

Al-Bayati, Firas A

2009-01-01

Background Mentha longifolia L. (Lamiaceae) leaves have been traditionally implemented in the treatment of minor sore throat and minor mouth or throat irritation by the indigenous people of Iraq, although the compounds responsible for the medicinal properties have not been identified. In the present study, an antimicrobial compound was isolated and characterized, and its biological activity was assessed. Methods The compound was isolated and characterized from the extracted essential oil using different spectral techniques: TLC, FTIR spectra and HPLC. Antimicrobial activity of the compound was assessed using both disc diffusion and microdilution method in 96 multi-well microtiter plates. Results A known compound was isolated from the essential oil of the plant and was identified as (-) menthol. The isolated compound was investigated for its antimicrobial activity against seven selected pathogenic and non-pathogenic microorganisms: Staphylococcus aureus, Streptococcus mutans, Streptococcus faecalis, Streptococcus pyogenis, Lactobacillus acidophilus, Pseudomonas aeruginosa and the yeast Candida albicans. Menthol at different concentrations (1:1, 1:5, 1:10, 1:20) was active against all tested bacteria except for P. aeruginosa, and the highest inhibitory effect was observed against S. mutans (zone of inhibition: 25.3 mm) using the disc diffusion method. Minimal inhibitory concentration MIC values ranged from 15.6–125.0 μg/ml, and the most promising results were observed against S. aureus and S. mutans (MIC 15.6 μg/ml) while, S. faecalis, S. pyogenis and L. acidophilus ranked next (MIC 31.2 μg/ml). Furthermore, menthol achieved considerable antifungal activity against the yeast C. albicans (zone of inhibition range: 7.1–18.5 mm; MIC: 125.0). Conclusion The isolation of an antimicrobial compound from M. longifolia leaves validates the use of this plant in the treatment of minor sore throat and minor mouth or throat irritation. PMID:19523224

Antimicrobial lectin from Schinus terebinthifolius leaf.

PubMed

Gomes, F S; Procópio, T F; Napoleão, T H; Coelho, L C B B; Paiva, P M G

2013-03-01

Schinus terebinthifolius leaves are used for treating human diseases caused by micro-organisms. This work reports the isolation, characterization and antimicrobial activity of S. terebinthifolius leaf lectin (SteLL). The isolation procedure involved protein extraction with 0.15 mol l(-1) NaCl, filtration through activated charcoal and chromatography of the filtrate on a chitin column. SteLL is a 14-kDa glycopeptide with haemagglutinating activity that is inhibited by N-acetyl-glucosamine, not affected by ions (Ca(2+) and Mg(2+)) and stable upon heating (30-100 °C) as well as over the pH 5.0-8.0. The antimicrobial effect of SteLL was evaluated by determining the minimal inhibitory (MIC), bactericide (MBC) and fungicide (MFC) concentrations. Lectin was active against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella enteritidis and Staphylococcus aureus. Highest bacteriostatic and bactericide effects were detected for Salm. enteritidis (MIC: 0.45 μg ml(-1)) and Staph. aureus (MBC: 7.18 μg ml(-1)), respectively. SteLL impaired the growth (MIC: 6.5 μg ml(-1)) and survival (MFC: 26 μg ml(-1)) of Candida albicans. SteLL, a chitin-binding lectin, purified in milligram quantities, showed antimicrobial activity against medically important bacteria and fungi. SteLL can be considered as a new biomaterial for potential antimicrobial applications. © 2012 The Society for Applied Microbiology.

Synthesis, spectroscopic characterization, DFT study and antimicrobial activity of novel alkylaminopyrazole derivatives

NASA Astrophysics Data System (ADS)

Zalaru, Christina; Dumitrascu, Florea; Draghici, Constantin; Tarcomnicu, Isabela; Tatia, Rodica; Moldovan, Lucia; Chifiriuc, Mariana-Carmen; Lazar, Veronica; Marinescu, Maria; Nitulescu, Mihai George; Ferbinteanu, Marilena

2018-03-01

A new series of substituted N,N-bis-[(1H-pyrazol-1-yl)methyl]-aminohexadecane Mannich bases were synthesized, characterized by IR, 1H NMR 13C NMR, UV-Vis, MS and elemental analysis, and tested for their biological activity. All the synthesized compounds were tested for in vitro antimicrobial activity against a panel of selected bacterial and fungal strains using erythromycin and clotrimazole as standards. Most of the synthesized compounds demonstrated very good activity at minimum inhibitory concentrations (MICs). Compound 3b with an halogen atom into the pharmacophore structure exhibited the most significant activity against Bacillus subtilis (MIC = 0.007 μgmLL-1) versus erythromycin as standard. In vitro cytotoxicity of the new compounds was studied using MTT assay. The analysis of the test cells showed that the newly synthesized alkylaminopyrazoles derivatives were biocompatible until a concentration of 5 μgmL-1; two compounds presented a high degree of biocompatibility on the studied concentration range.

Synthesis, characterization and anti-microbial activity of phenylurea-formaldehyde resin (PUF) and its polymer metal complexes (PUF-Mn(II).

PubMed

Ahamad, Tansir; Alshehri, Saad M

2012-10-01

Phenylurea-formaldehyde polymer (PUF) was synthesized via polycondensation of phenylurea and formaldehyde in basic medium, its polymer-metal complexes [PUF-M(II)] were prepared with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) ions. PUF and PUF-M(II) were characterized with magnetic moment measurements, elemental and spectral (UV-visible, FTIR, 1H-NMR, 13C-NMR and ESR) analysis. The thermal behaviors of all the synthesized polymers were carried out using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The thermal data revealed that all of the PUF-M(II) showed higher thermal stabilities than the PUF and also ascribed that the PUF-Cu(II) showed better thermal stability than the other PUF-M(II). The kinetic parameters such as activation energy, pre-exponential factor etc., were evaluated for these polymer metal complexes using Coats-Redfern equation. In addition, the antimicrobial activity of the synthesized polymers was tested against several microorganisms using agar well diffusion methods. Among all of the PUF-M(II), the antimicrobial activity of the PUF-Cu(II) showed the highest zone of inhibition because of its higher stability constant and may be used in biomedical applications. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparative evaluation of antibacterial activity of caffeic acid phenethyl ester and PLGA nanoparticle formulation by different methods

NASA Astrophysics Data System (ADS)

Arasoglu, Tülin; Derman, Serap; Mansuroglu, Banu

2016-01-01

The aim of the present study was to evaluate the antimicrobial activity of nanoparticle and free formulations of the CAPE compound using different methods and comparing the results in the literature for the first time. In parallel with this purpose, encapsulation of CAPE with the PLGA nanoparticle system (CAPE-PLGA-NPs) and characterization of nanoparticles were carried out. Afterwards, antimicrobial activity of free CAPE and CAPE-PLGA-NPs was determined using agar well diffusion, disk diffusion, broth microdilution and reduction percentage methods. P. aeroginosa, E. coli, S. aureus and methicillin-resistant S. aureus (MRSA) were chosen as model bacteria since they have different cell wall structures. CAPE-PLGA-NPs within the range of 214.0 ± 8.80 nm particle size and with an encapsulation efficiency of 91.59 ± 4.97% were prepared using the oil-in-water (o-w) single-emulsion solvent evaporation method. The microbiological results indicated that free CAPE did not have any antimicrobial activity in any of the applied methods whereas CAPE-PLGA-NPs had significant antimicrobial activity in both broth dilution and reduction percentage methods. CAPE-PLGA-NPs showed moderate antimicrobial activity against S. aureus and MRSA strains particularly in hourly measurements at 30.63 and 61.25 μg ml-1 concentrations (both p < 0.05), whereas they failed to show antimicrobial activity against Gram-negative bacteria (P. aeroginosa and E. coli, p > 0.05). In the reduction percentage method, in which the highest results of antimicrobial activity were obtained, it was observed that the antimicrobial effect on S. aureus was more long-standing (3 days) and higher in reduction percentage (over 90%). The appearance of antibacterial activity of CAPE-PLGA-NPs may be related to higher penetration into cells due to low solubility of free CAPE in the aqueous medium. Additionally, the biocompatible and biodegradable PLGA nanoparticles could be an alternative to solvents such as ethanol, methanol or DMSO. Consequently, obtained results show that the method of selection is extremely important and will influence the results. Thus, broth microdilution and reduction percentage methods can be recommended as reliable and useful screening methods for determination of antimicrobial activity of PLGA nanoparticle formulations used particularly in drug delivery systems compared to both agar well and disk diffusion methods.

Lipoic acid functionalized SiO2@Ag nanoparticles. Synthesis, characterization and evaluation of biological activity.

PubMed

Tudose, Madalina; Culita, Daniela Cristina; Musuc, Adina Magdalena; Somacescu, Simona; Ghica, Cornel; Chifiriuc, Mariana Carmen; Bleotu, Coralia

2017-10-01

A novel nanocomposite was obtained through the covalent immobilization of lipoic acid on the surface of silver nanoparticles-decorated silica nanoparticles (SiO 2 @Ag). The hybrid organic - inorganic material obtained was characterized by Fourier transform infrared spectroscopy, thermal analysis, scanning and transmision electron microscopy, X-ray photoelectron spectroscopy and UV-Visible spectroscopy. Its antioxidant, cytotoxic, antimicrobial activity and influence on mammalian cells cycle were evaluated. The results of this study have shown that the functionalization of SiO 2 @Ag with lipoic acid resulted in a composite with increased specificity of interaction with different mammalian cell lines and antioxidant activity, but with decreased cytotoxicity and antimicrobial properties. Therefore, the SiO 2 @Ag functionalized with lipoic acid could be successfully used in certain concentrations to modulate the cell cycle, in order to obtain the desired anti-proliferative or stimulatory therapeutic effect. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis, structural characterization, antimicrobial activities and theoretical investigations of some 4-(4-aminophenylsulfonyl) phenylimino) methyl)-4-(aryldiazenyl) phenol

NASA Astrophysics Data System (ADS)

Ghasemian, Motaleb; Kakanejadifard, Ali; Karami, Tahereh

2016-11-01

The azo-azomethine dyes with a different substitution have been designed from the reaction of 4,4‧-diaminodiphenyl sulfone with 2-hydroxy-5-(aryldiazenyl)benzaldehyde. The compounds have been characterized by elemental analysis, Mass, IR, UV-Vis, TGA-DTA and NMR spectroscopy. The solvatochromism behaviors, effects of substitution and pH on the electronic absorption spectra of dyes were evaluated. The in vitro antimicrobial activities were also screened for their potential for antibiotic activities by broth micro dilution method. Also, the optimum molecular geometries, molecular electrostatic potential (MEP), nucleus-independent chemical shift (NICS) and frontier molecular orbitals (FMO), vibrational spectra (IR) and electronic absorption (UV-Vis) spectra of the title compounds have been investigated with the help of DFT and TDDFT methods with 6-311 ++G(d,p) basis sets and PCM calculations. The results of the calculations show excellent agreement with the experimental value.

A Simultaneously Antimicrobial, Protein-Repellent, and Cell-Compatible Polyzwitterion Network.

PubMed

Kurowska, Monika; Eickenscheidt, Alice; Guevara-Solarte, Diana-Lorena; Widyaya, Vania Tanda; Marx, Franziska; Al-Ahmad, Ali; Lienkamp, Karen

2017-04-10

A simultaneously antimicrobial, protein-repellent, and cell-compatible surface-attached polymer network is reported, which reduces the growth of bacterial biofilms on surfaces through its multifunctionality. The coating was made from a poly(oxonorbornene)-based zwitterion (PZI), which was surface-attached and cross-linked in one step by simultaneous UV-activated CH insertion and thiol-ene reaction. The process was applicable to both laboratory surfaces like silicon, glass, and gold and real-life surfaces like polyurethane foam wound dressings. The chemical structure and physical properties of the PZI surface and the two reference surfaces SMAMP ("synthetic mimic of an antimicrobial peptide"), an antimicrobial but protein-adhesive polymer coating, and PSB (poly(sulfobetaine)), a protein-repellent but not antimicrobial polyzwitterion coating were characterized by Fourier transform infrared spectroscopy, ellipsometry, contact angle measurements, photoelectron spectroscopy, swellability measurements (using surface plasmon resonance spectroscopy, SPR), zeta potential measurements, and atomic force microscopy. The time-dependent antimicrobial activity assay (time-kill assay) confirmed the high antimicrobial activity of the PZI; SPR was used to demonstrate that it was also highly protein-repellent. Biofilm formation studies showed that the material effectively reduced the growth of Escherichia coli and Staphylococcus aureus biofilms. Additionally, it was shown that the PZI was highly compatible with immortalized human mucosal gingiva keratinocytes and human red blood cells using the Alamar Blue assay, the live-dead stain, and the hemolysis assay. PZI thus may be an attractive coating for biomedical applications, particularly for the fight against bacterial biofilms on medical devices and in other applications.

Expanding the Bioactive Chemical Space of Anthrabenzoxocinones through Engineering the Highly Promiscuous Biosynthetic Modification Steps.

PubMed

Mei, Xianyi; Yan, Xiaoli; Zhang, Hui; Yu, Mingjia; Shen, Guangqing; Zhou, Linjun; Deng, Zixin; Lei, Chun; Qu, Xudong

2018-01-19

Anthrabenzoxocinones (ABXs) including (-)-ABXs and (+)-ABXs are a group of bacterial FabF-specific inhibitors with potent antimicrobial activity of resistant strains. Optimization of their chemical structures is a promising method to develop potent antibiotics. Through biosynthetic investigation, we herein identified and characterized two highly promiscuous enzymes involved in the (-)-ABX structural modification. The promiscuous halogenase and methyltransferase can respectively introduce halogen-modifications into various positions of the ABX scaffolds and methylation to highly diverse substrates. Manipulation of their activity in both of the (-)-ABXs and (+)-ABXs biosyntheses led to the generation of 14 novel ABX analogues of both enantiomers. Bioactivity assessment revealed that a few of the analogues showed significantly improved antimicrobial activity, with the C3-hydroxyl and chlorine substitutions critical for their activity. This study enormously expands the bioactive chemical space of the ABX family and FabF-specific inhibitors. The disclosed broad-selective biosynthetic machineries and structure-activity relationship provide a solid basis for further generation of potent antimicrobial agents.

Preparation and Characterization of Ternary Antimicrobial Films of β-Cyclodextrin/Allyl Isothiocyanate/Polylactic Acid for the Enhancement of Long-Term Controlled Release

PubMed Central

Wang, Jinpeng; Qiu, Chao; Narsimhan, Ganesan; Jin, Zhengyu

2017-01-01

Allyl isothiocyanate (AITC) are natural essential oil components that have outstanding antimicrobial activities. However, low water solubility, high volatility, and easy degradation by heat, restricting their application in food packing industry. Development of the inclusion complex of β-cyclodextrin/AITC (β-CD/AITC) is a promising solution. Furthermore, the incorporation of β-CD/AITC complex into polylactic acid (PLA) films would be an attractive method to develop food antimicrobial materials. The aim of this study was to evaluate the enhancement in physicochemical properties, antimicrobial activities, and controlled release of β-CD/AITC from such films. The addition of β-CD/AITC significantly increased the flexibility and thermal stability of films. The Fourier transform infrared (FTIR) results revealed that the interactions between β-CD/AITC and PLA films occurred. The controlled release of AITC encapsulated in β-CD was significantly affected by relative humidity and temperature. The PLA films containing β-CD/AITC can be applied as an effective antimicrobial packing material for food and non-food applications. PMID:29053573

The intrinsic antimicrobial activity of citric acid-coated manganese ferrite nanoparticles is enhanced after conjugation with the antifungal peptide Cm-p5

PubMed Central

Lopez-Abarrategui, Carlos; Figueroa-Espi, Viviana; Lugo-Alvarez, Maria B; Pereira, Caroline D; Garay, Hilda; Barbosa, João ARG; Falcão, Rosana; Jiménez-Hernández, Linnavel; Estévez-Hernández, Osvaldo; Reguera, Edilso; Franco, Octavio L; Dias, Simoni C; Otero-Gonzalez, Anselmo J

2016-01-01

Diseases caused by bacterial and fungal pathogens are among the major health problems in the world. Newer antimicrobial therapies based on novel molecules urgently need to be developed, and this includes the antimicrobial peptides. In spite of the potential of antimicrobial peptides, very few of them were able to be successfully developed into therapeutics. The major problems they present are molecule stability, toxicity in host cells, and production costs. A novel strategy to overcome these obstacles is conjugation to nanomaterial preparations. The antimicrobial activity of different types of nanoparticles has been previously demonstrated. Specifically, magnetic nanoparticles have been widely studied in biomedicine due to their physicochemical properties. The citric acid-modified manganese ferrite nanoparticles used in this study were characterized by high-resolution transmission electron microscopy, which confirmed the formation of nanocrystals of approximately 5 nm diameter. These nanoparticles were able to inhibit Candida albicans growth in vitro. The minimal inhibitory concentration was 250 µg/mL. However, the nanoparticles were not capable of inhibiting Gram-negative bacteria (Escherichia coli) or Gram-positive bacteria (Staphylococcus aureus). Finally, an antifungal peptide (Cm-p5) from the sea animal Cenchritis muricatus (Gastropoda: Littorinidae) was conjugated to the modified manganese ferrite nanoparticles. The antifungal activity of the conjugated nanoparticles was higher than their bulk counterparts, showing a minimal inhibitory concentration of 100 µg/mL. This conjugate proved to be nontoxic to a macrophage cell line at concentrations that showed antimicrobial activity. PMID:27563243

Characterization of growth inhibition of oral bacteria by sophorolipid using a microplate-format assay

USDA-ARS?s Scientific Manuscript database

Sophorolipid (SL) is a class of glycolipid biosurfactant produced by yeast and has potent antimicrobial activity against many microorganisms. In this paper, a microplate-based method was developed to characterize the growth inhibition by SL on five representative species of caries-causing oral bact...

Preparation and characterization of iron oxide magnetic nanoparticles functionalized by nisin.

PubMed

Gruskiene, Ruta; Krivorotova, Tatjana; Staneviciene, Ramune; Ratautas, Dalius; Serviene, Elena; Sereikaite, Jolanta

2018-05-08

Nisin is a known bacteriocin approved as a food additive for food preservation. It exhibits a wide spectrum antimicrobial activity against Gram-positive bacteria. Iron oxide magnetic nanoparticles were synthesized and characterized by X-ray diffraction method. A main part of iron oxide nanoparticles was found to be maghemite though a small quantity of magnetite could also be present. Magnetic nanoparticles were stabilized by citric, ascorbic, gallic or glucuronic acid coating. Stable iron oxide magnetic nanoparticles were functionalized by nisin using a simple and low cost adsorption method. Nisin loading was confirmed by FT-IR spectra, thermogravimetric analysis, dynamic light scattering and atomic force microscopy methods. Nisin-loaded iron oxide magnetic nanoparticles were stable at least six weeks as judged by the measurements of zeta-potential and hydrodynamic diameter. The antimicrobial activity of nisin-loaded iron oxide magnetic nanoparticles was demonstrated toward Gram-positive bacteria. Functionalized nanoparticles could therefore find the application as antimicrobials in innovative and emerging technologies based on the magnetic field. Copyright © 2018 Elsevier B.V. All rights reserved.

Characterization of Antimicrobial Agent Loaded Eudragit RS Solvent Exchange-Induced In Situ Forming Gels for Periodontitis Treatment.

PubMed

Phaechamud, Thawatchai; Jantadee, Takron; Mahadlek, Jongjan; Charoensuksai, Purin; Pichayakorn, Wiwat

2017-02-01

Eudragit RS (ERS), a quaternary polyacrylate positively charged polymer, exhibits a very low permeability and swells in aqueous media independently of pH without dissolving. Owing to its high solubility in N-methyl pyrrolidone (NMP), it was interesting to apply as polymer matrix for solvent-exchanged in situ forming gel. The aim of this research was to prepare in situ forming gels from ERS to deliver the antimicrobial agents (doxycycline hyclate, metronidazole, and benzoyl peroxide) for periodontitis treatment. They were evaluated for viscosity and rheology, gel formation, syringeability, drug release, and antimicrobial activities. The solvent exchange between NMP and an external aqueous simulated gingival crevicular fluid stimulated the dissolved ERS transforming into the opaque rigid gel. Antimicrobial agent loaded ERS systems exhibited Newtonian flow with acceptable syringeability. The higher-loaded ERS promoted the more prolongation of drug release because of the retardation of water diffusion into the precipitated matrix. Antimicrobial activities against Staphylococcus aureus, Escherichia coli, Candida albicans, Streptococcus mutans, and Porphyromonas gingivalis depended on type of drugs and test microorganisms. Doxycycline hyclate loaded ERS systems showed these activities greater than the others; however, all of them could inhibit all test microorganisms. Thus, the solvent exchange-induced in situ forming gels comprising ERS-antimicrobial drugs exhibited potential use as localized delivery systems for periodontitis treatment.

Bioprotective Role of Yeasts

PubMed Central

Muccilli, Serena; Restuccia, Cristina

2015-01-01

The yeasts constitute a large group of microorganisms characterized by the ability to grow and survive in different and stressful conditions and then to colonize a wide range of environmental and human ecosystems. The competitive traits against other microorganisms have attracted increasing attention from scientists, who proposed their successful application as bioprotective agents in the agricultural, food and medical sectors. These antagonistic activities rely on the competition for nutrients, production and tolerance of high concentrations of ethanol, as well as the synthesis of a large class of antimicrobial compounds, known as killer toxins, which showed clearly a large spectrum of activity against food spoilage microorganisms, but also against plant, animal and human pathogens. This review describes the antimicrobial mechanisms involved in the antagonistic activity, their applications in the processed and unprocessed food sectors, as well as the future perspectives in the development of new bio-drugs, which may overcome the limitations connected to conventional antimicrobial and drug resistance. PMID:27682107

Biosynthesis of silver nanoparticles using Ocimum sanctum (Tulsi) leaf extract and screening its antimicrobial activity

NASA Astrophysics Data System (ADS)

Singhal, Garima; Bhavesh, Riju; Kasariya, Kunal; Sharma, Ashish Ranjan; Singh, Rajendra Pal

2011-07-01

Development of green nanotechnology is generating interest of researchers toward ecofriendly biosynthesis of nanoparticles. In this study, biosynthesis of stable silver nanoparticles was done using Tulsi ( Ocimum sanctum) leaf extract. These biosynthesized nanoparticles were characterized with the help of UV-vis spectrophotometer, Atomic Absorption Spectroscopy (AAS), Dynamic light scattering (DLS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Transmission electron microscopy (TEM). Stability of bioreduced silver nanoparticles was analyzed using UV-vis absorption spectra, and their antimicrobial activity was screened against both gram-negative and gram-positive microorganisms. It was observed that O. sanctum leaf extract can reduce silver ions into silver nanoparticles within 8 min of reaction time. Thus, this method can be used for rapid and ecofriendly biosynthesis of stable silver nanoparticles of size range 4-30 nm possessing antimicrobial activity suggesting their possible application in medical industry.

SYNTHESIS AND BIOLOGICAL EVALUATION OF N-(SUBSTITUTED PHENYL)-2-(5H-[1,2,4]TRIAZINO[5,6-b]INDOL-3-YLSULFANYL)ACETAMIDES AS ANTIMICROBIAL, ANTIDEPRESSANT AND ANTICONVULSANT AGENTS.

PubMed

Shruthi, N; Poojary, Boja; Kumar, Vasantha; Prathibha, A; Hussain, Mumtaz Mohammed; Revanasiddappa, B C; Joshi, Himanshu

2015-01-01

A new series of N-Aryl-2-(5H-[1,2,4]triazino[5,6-b]indol-3-ylsulfanyl)acetamides were synthesized by condensation of tricyclic compound 2,5-dihydro-3H-[1,2,4]triazino[5,6-b]indole-3-thione with chloro N-phenylacetamides. The tricyclic compound was obtained by condensation of Isatin with thiosemicarbazide. Chloro N-phenylacetamides were obtained from different substituted anilines. Their structures were characterized by IR, 1H NMR, LC-MS and elemental analyses. Newly synthesized compounds were screened for antimicrobial, antidepressant and anticonvulsant activities. Preliminary results indicated that most of the compounds showed lesser MIC value than the standard drug used when tested for antimicrobial activity. Some of the compounds were endowed with very good antidepressant and anticonvulsant activity.

Influence of CuO nanoparticle on palm oil based alkyd resin preparation and its antimicrobial activity

NASA Astrophysics Data System (ADS)

Ruey Ong, Huei; Maksudur Rahman Khan, Md.; Ramli, Ridzuan; Shein Hong, Chi; Yunus, Rosli Mohd

2018-03-01

An alkyd resin has been synthesized from palm oil that reacted with glycerol and phthalic anhydride by alcoholysis-polyesterification process and co-catalyzed by CuO nanoparticle. The CuO nanoparticle was pre-prepared in the glycerol via sol gel method, which creates a new reaction condition for resin preparation. The resins were characterized by fourier transform infrared spectroscopy (FTIR), where a new ester linkage bond (C-O-C) was noticed for resin sample. The antimicrobial activity and the curing behaviour of the resin were determined by Kirby-Bauer and differential scanning calorimeter technique. It was found that, the addition of CuO speeded up the reaction rate and played antimicrobial role. Moreover, it shortens the reaction time of alcoholysis and polyesterification process.

Green synthesis and characterization of monodispersed silver nanoparticles using root bark aqueous extract of Annona muricata Linn and their antimicrobial activity

NASA Astrophysics Data System (ADS)

Ezealisiji, K. M.; Noundou, X. S.; Ukwueze, S. E.

2017-11-01

In recent time, various phytosynthetic methods have been employed for the fabrication of silver nanoparticles; these unique metal nanoparticles are used in several applications which include pharmaceuticals and material engineering. The current research reports a rapid and simple synthetic partway for silver nanoparticles (AgNPs) using root bark aqueous extract of Annona muricata and the evaluation of its antimicrobial efficacy against pathogenic microorganisms. The root bark extract was treated with aqueous silver nitrate solution. Silver ions were reduced to silver atoms which on aggregation gave Silver nanoparticles; the biosynthesized AgNPs were characteristically spherical, discreet and stabilized by phytochemical entities and were characterized using ultraviolet visible spectroscopy, transmission electron microscope (TEM) and photon correlation microscopy. The aqueous plant extract-AgNPs suspension was subjected to Fourier transform infrared spectroscopy. TEM result for the average particle size is 22 ± 2 nm. The polydispersity index and zeta-potential were found to be 0.44 ± 0.02 and - 27.90 ± 0.01 mV, respectively (Zeta-Sizer). The antimicrobial evaluation result showed that the synthesized silver nanoparticles at different concentration were very active against the Gram-positive bacteria ( B. subtilis, S. aureous) and Gram-negative bacteria ( K. Pneumonia, E. Coli and Pseudomonas aeruginosa), P. aeruginosa being most susceptible to the anti microbial effect of the silver nanoparticles. Stable silver nanoparticles with antimicrobial activity were obtained through biosynthesis.

Antimicrobial activity of biopolymeric thin films containing flavonoid natural compounds and silver nanoparticles fabricated by MAPLE: A comparative study

NASA Astrophysics Data System (ADS)

Cristescu, R.; Visan, A.; Socol, G.; Surdu, A. V.; Oprea, A. E.; Grumezescu, A. M.; Chifiriuc, M. C.; Boehm, R. D.; Yamaleyeva, D.; Taylor, M.; Narayan, R. J.; Chrisey, D. B.

2016-06-01

The purpose of this study was to investigate the interactions between microorganisms, including the planktonic and adherent organisms, and biopolymer (polyvinylpyrrolidone), flavonoid (quercetin dihydrate and resveratrol)-biopolymer, and silver nanoparticles-biopolymer composite thin films that were deposited using matrix assisted pulsed laser evaporation (MAPLE). A pulsed KrF* excimer laser source was used to deposit the aforementioned composite thin films, which were characterized using Fourier transform infrared spectroscopy (FT-IR), infrared microscopy (IRM), scanning electron microscopy (SEM), Grazing incidence X-ray diffraction (GIXRD) and atomic force microscopy (AFM). The antimicrobial activity of thin films was quantified using an adapted disk diffusion assay against Gram-positive and Gram-negative bacteria strains. FT-IR, AFM and SEM studies confirmed that MAPLE may be used to fabricate thin films with chemical properties corresponding to the input materials as well as surface properties that are appropriate for medical use. The silver nanoparticles and flavonoid-containing films exhibited an antimicrobial activity both against Gram-positive and Gram-negative bacterial strains demonstrating the potential use of these hybrid systems for the development of novel antimicrobial strategies.

La(III) complex involving the O,N-donor environment of quinazoline-4(3H)-one Schiff’s base and their antimicrobial attributes against methicillin-resistant Staphylococcus aureus (MRSA)

NASA Astrophysics Data System (ADS)

Siddappa, K.; Mane, Sunilkumar B.; Manikprabhu, Deene

2014-09-01

The incidence of methicillin-resistant Staphylococcus aureus increased during the past few decades, so there is an urgent need of new antimicrobial agents if public health is concerned. Though the Schiff’s bases and La(III) complex have enormous biological activity, but less attention was given in their synthesis. In the present investigation, we synthesized a new (E)-3-((2-hydroxynaphthalen-1-yl) methyleneamino)-2-methylquinazoline-4(3H)-one HNMAMQ Schiff’s base by the condensation of 3-(2-aminophenyl) quinazolin-2-methyl-4(3H)-one and 2-hydroxy-1-naphthaldehyde. The Schiff’s base HNMAMQ and its La(III) complex were characterized by elemental analyses, IR, NMR, mass spectra, and thermal studies. The newly synthesized Schiff’s base HNMAMQ and its La(III) complex were evaluated for their antimicrobial activity against methicillin-resistant Staphylococcus aureus isolated from the Gulbarga region in India. The Schiff’s base HNMAMQ and its La(III) complex showed good antimicrobial activity and thus represents a potential new drug of choice.

Evaluation of antimicrobial activity of silver nanoparticles for carboxymethylcellulose film applications in food packaging.

PubMed

Siqueira, Maria C; Coelho, Gustavo F; de Moura, Márcia R; Bresolin, Joana D; Hubinger, Silviane Z; Marconcini, José M; Mattoso, Luiz H C

2014-07-01

In this study, silver nanoparticles were prepared and incorporated into carboxymethylcellulose films to evaluate the antimicrobial activity for food packaging applications. The techniques carried out for material characterization were: infrared spectroscopy and thermal analysis for the silver nanoparticles and films, as well as particle size distribution for the nanoparticles and water vapor permeability for the films. The antimicrobial activity of silver nanoparticles prepared by casting method was investigated. The minimum inhibitory concentration (MIC) value of the silver nanoparticles to test Gram-positive (Enterococcus faecalis) and Gram-negative (Escherichia coli) microorganisms was carried out by the serial dilution technique, tested in triplicate to confirm the concentration used. The results were developed using the Mcfarland scale which indicates that the presence or absence of turbidity tube demonstrates the inhibition of bacteria in relation to the substance inoculated. It was found that the silver nanoparticles inhibited the growth of the tested microorganisms. The carboxymethylcellulose film embedded with silver nanoparticles showed the best antimicrobial effect against Gram-positive (E. faecalis) and Gram-negative (E. coli) bacteria (0.1 microg cm(-3)).

Structural characterization and antimicrobial properties of silver nanoparticles prepared by inverse microemulsion method.

PubMed

Wani, Irshad A; Khatoon, Sarvari; Ganguly, Aparna; Ahmed, Jahangeer; Ahmad, Tokeer; Manzoor, Nikhat

2013-01-01

Silver nanoparticles have been synthesized in the inverse microemulsions formed using three different surfactants viz., cetyl-trimethyl ammonium bromide (CTAB), Tergitol and Triton X-100. We have done a systematic study of the effect of the surfactants on the particle size and properties of the silver nanoparticles. Microscopic studies show the formation of spheres, cubes and discs shaped silver nanostructures with the size in the range from 8 to 40 nm. Surface plasmon resonance (SPR) peak was observed around 400 nm and 500 nm. In addition to SPR some extra peaks have also been observed due to the formation of silver metal clusters. The surface area increases from 3.45 to 15.06 m(2)/g with decreasing the size of silver nanoparticles (40-8 nm). To investigate the antimicrobial activity of silver nanoparticles, the nanoparticles were tested against the yeast, Candida albicans and the bacterium, E. coli. The results suggest very good antimicrobial activity of the silver nanoparticles against the test microbes. The mode of action of the antimicrobial activity was also proposed. Copyright © 2012 Elsevier B.V. All rights reserved.

Ocellatin peptides from the skin secretion of the South American frog Leptodactylus labyrinthicus (Leptodactylidae): characterization, antimicrobial activities and membrane interactions.

PubMed

Gusmão, Karla A G; Dos Santos, Daniel M; Santos, Virgílio M; Cortés, María Esperanza; Reis, Pablo V M; Santos, Vera L; Piló-Veloso, Dorila; Verly, Rodrigo M; de Lima, Maria Elena; Resende, Jarbas M

2017-01-01

The availability of antimicrobial peptides from several different natural sources has opened an avenue for the discovery of new biologically active molecules. To the best of our knowledge, only two peptides isolated from the frog Leptodactylus labyrinthicus , namely pentadactylin and ocellatin-F1, have shown antimicrobial activities. Therefore, in order to explore the antimicrobial potential of this species, we have investigated the biological activities and membrane interactions of three peptides isolated from the anuran skin secretion. Three peptide primary structures were determined by automated Edman degradation. These sequences were prepared by solid-phase synthesis and submitted to activity assays against gram-positive and gram-negative bacteria and against two fungal strains. The hemolytic properties of the peptides were also investigated in assays with rabbit blood erythrocytes. The conformational preferences of the peptides and their membrane interactions have been investigated by circular dichroism spectroscopy and liposome dye release assays. The amino acid compositions of three ocellatins were determined and the sequences exhibit 100% homology for the first 22 residues (ocellatin-LB1 sequence). Ocellatin-LB2 carries an extra Asn residue and ocellatin-F1 extra Asn-Lys-Leu residues at C-terminus. Ocellatin-F1 presents a stronger antibiotic potential and a broader spectrum of activities compared to the other peptides. The membrane interactions and pore formation capacities of the peptides correlate directly with their antimicrobial activities, i.e., ocellatin-F1 > ocellatin-LB1 > ocellatin-LB2. All peptides acquire high helical contents in membrane environments. However, ocellatin-F1 shows in average stronger helical propensities. The obtained results indicate that the three extra amino acid residues at the ocellatin-F1 C-terminus play an important role in promoting stronger peptide-membrane interactions and antimicrobial properties. The extra Asn-23 residue present in ocellatin-LB2 sequence seems to decrease its antimicrobial potential and the strength of the peptide-membrane interactions.

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

PubMed

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

2013-01-01

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

Antimicrobial activity of extracts from macroalgae Ulva lactuca against clinically important Staphylococci is impacted by lunar phase of macroalgae harvest.

PubMed

Deveau, A M; Miller-Hope, Z; Lloyd, E; Williams, B S; Bolduc, C; Meader, J M; Weiss, F; Burkholder, K M

2016-05-01

Staphylococcus aureus is a common human bacterial pathogen that causes skin and soft tissue infections. Methicillin-resistant Staph. aureus (MRSA) are increasingly drug-resistant, and thus there is great need for new therapeutics to treat Staph. aureus infections. Attention has focused on potential utility of natural products, such as extracts of marine macroalgae, as a source of novel antimicrobial compounds. The green macroalgae Ulva lactuca produces compounds inhibitory to human pathogens, although the effectiveness of U. lactuca extracts against clinically relevant strains of Staph. aureus is poorly understood. In addition, macroalgae produce secondary metabolites that may be influenced by exogenous factors including lunar phase, but whether lunar phase affects U. lactuca antimicrobial capacity is unknown. We sought to evaluate the antibacterial properties of U. lactuca extracts against medically important Staphylococci, and to determine the effect of lunar phase on antimicrobial activity. We report that U. lactuca methanolic extracts inhibit a range of Staphylococci, and that lunar phase of macrolagae harvest significantly impacts antimicrobial activity, suggesting that antimicrobial properties can be maximized by manipulating time of algal harvest. These findings provide useful parameters for future studies aimed at isolating and characterizing U. lactuca anti-Staphylococcal agents. The growing prevalence of antibiotic-resistant human pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) has intensified efforts towards discovery and development of novel therapeutics. Marine macroalgae like Ulva lactuca are increasingly recognized as potential sources of antimicrobials, but the efficacy of U. lactuca extracts against common, virulent strains of Staph. aureus is poorly understood. We demonstrate that U. lactuca methanolic extracts inhibit a variety of clinically relevant Staphylococcus strains, and that the antimicrobial activity can be maximized by optimizing time of algal harvest. These findings provide potentially useful parameters for future work of isolating and identifying novel antimicrobial agents from macroalgae. © 2016 The Society for Applied Microbiology.

Ultrathin hexagonal MgO nanoflakes coated medical textiles and their enhanced antibacterial activity

NASA Astrophysics Data System (ADS)

Veeran Ponnuvelu, Dinesh; Selvaraj, Aravind; Prema Suriyaraj, Shanmugam; Selvakumar, Rajendran; Pulithadathail, Biji

2016-10-01

A facile hydrothermal method for development of ultrathin MgO nanoplates from different precursors and their enhanced antibacterial activity after coating onto medical textiles is reported. Ultrathin MgO nanoplates having hexagonal structure were characterized using UV-visible spectroscopy, atomic force microscopy, field emission scanning electron microscopy, x-ray diffraction and high resolution transmission electron microscopy. The formation of MgO nanoplates was found to exhibit profound anionic effect leading to ultrathin, planar structures with exposed MgO [111] facets, which may be responsible for enhanced antimicrobial activity. Medical fabrics (bleached 100% cotton) were coated with MgO nanoplates using pad-dry-cure method. The antibacterial activity of these fabrics was tested against Bacillus subtilis and Escherichia coli. The MgO nanoplates coated onto the fabric were found to have good adherence properties owing to their two-dimensional structure and were durable even after repeated washings without substantial reduction in the antimicrobial activity. The enhanced antibacterial activity may be attributed to the presence of oxygen vacancies, surface oxygen anions and hydroxyl groups on the surface of MgO nanoplates. This cost-effective functional finish (anti-microbial) to cotton fabric using MgO nanoplates may be suitable for many prospective medical applications and can serve as an alternative to the costlier silver based antimicrobial textiles.

Broad-spectrum antimicrobial epiphytic and endophytic fungi from marine organisms: isolation, bioassay and taxonomy.

PubMed

Zhang, Yi; Mu, Jun; Feng, Yan; Kang, Yue; Zhang, Jia; Gu, Peng-Juan; Wang, Yu; Ma, Li-Fang; Zhu, Yan-Hua

2009-04-17

In the search for new marine derived antibiotics, 43 epi- and endophytic fungal strains were isolated from the surface or the inner tissue of different marine plants and invertebrates. Through preliminary and secondary screening, 10 of them were found to be able to produce broad-spectrum antimicrobial metabolites. By morphological and molecular biological methods, three active strains were characterized to be Penicillium glabrum, Fusarium oxysporum, and Alternaria alternata.

Antimicrobial and antioxidant activity of essential oil and different plant extracts of Psidium cattleianum Sabine.

PubMed

Scur, M C; Pinto, F G S; Pandini, J A; Costa, W F; Leite, C W; Temponi, L G

2016-02-01

The goals of the study were to determinethe antimicrobial and antioxidant activities of essential oil and plant extracts aqueous and ethanolic of Psidium cattleianum Sabine; the chemical composition of the essential oil of P. cattleianum; and the phytochemical screening of aqueous and ethanolic extracts of the same plant. Regarding the antimicrobial activity, the ethanolic extract exhibited moderate antimicrobial activity with respect to bacteria K. pneumoniae and S. epidermidis, whereas, regarding other microorganisms, it showed activity considered weak. The aqueous extract and the essential oil showed activity considered weak, although they inhibited the growth of microorganisms. About the antioxidant potential, the ethanolic and aqueous extracts exhibited a scavenging index exceeding 90%, while the essential oil didn´t show significant antioxidant activity. Regarding the phytochemical composition, the largest class of volatile compounds identified in the essential oil of P. cattleianum included the following terpenic hydrocarbons: α-copaene (22%); eucalyptol (15%), δ-cadinene (9.63%) and α-selinene (6.5%). The phytochemical screening of extracts showed the presence of tannins, flavonoids, and triterpenoids for aqueous and ethanolic extracts. The extracts and essential oils inhibit the growth of microrganisms and plant extracts showed significant antioxidant activity. Also, the phytochemical characterization of the essential oil showed the presence of compounds interest commercial, as well as extracts showed the presence of important classes and compounds with biological activities.

Chemical Changes in Nonthermal Plasma-Treated N-Acetylcysteine (NAC) Solution and Their Contribution to Bacterial Inactivation.

PubMed

Ercan, Utku K; Smith, Josh; Ji, Hai-Feng; Brooks, Ari D; Joshi, Suresh G

2016-02-02

In continuation of our previous reports on the broad-spectrum antimicrobial activity of atmospheric non-thermal dielectric barrier discharge (DBD) plasma treated N-Acetylcysteine (NAC) solution against planktonic and biofilm forms of different multidrug resistant microorganisms, we present here the chemical changes that mediate inactivation of Escherichia coli. In this study, the mechanism and products of the chemical reactions in plasma-treated NAC solution are shown. UV-visible spectrometry, FT-IR, NMR, and colorimetric assays were utilized for chemical characterization of plasma treated NAC solution. The characterization results were correlated with the antimicrobial assays using determined chemical species in solution in order to confirm the major species that are responsible for antimicrobial inactivation. Our results have revealed that plasma treatment of NAC solution creates predominantly reactive nitrogen species versus reactive oxygen species, and the generated peroxynitrite is responsible for significant bacterial inactivation.

Chemical Changes in Nonthermal Plasma-Treated N-Acetylcysteine (NAC) Solution and Their Contribution to Bacterial Inactivation

PubMed Central

Ercan, Utku K.; Smith, Josh; Ji, Hai-Feng; Brooks, Ari D.; Joshi, Suresh G.

2016-01-01

In continuation of our previous reports on the broad-spectrum antimicrobial activity of atmospheric non-thermal dielectric barrier discharge (DBD) plasma treated N-Acetylcysteine (NAC) solution against planktonic and biofilm forms of different multidrug resistant microorganisms, we present here the chemical changes that mediate inactivation of Escherichia coli. In this study, the mechanism and products of the chemical reactions in plasma-treated NAC solution are shown. UV-visible spectrometry, FT-IR, NMR, and colorimetric assays were utilized for chemical characterization of plasma treated NAC solution. The characterization results were correlated with the antimicrobial assays using determined chemical species in solution in order to confirm the major species that are responsible for antimicrobial inactivation. Our results have revealed that plasma treatment of NAC solution creates predominantly reactive nitrogen species versus reactive oxygen species, and the generated peroxynitrite is responsible for significant bacterial inactivation. PMID:26832829

Powerful workhorses for antimicrobial peptide expression and characterization.

PubMed

Li, Chun; Blencke, Hans-Matti; Paulsen, Victoria; Haug, Tor; Stensvåg, Klara

2010-01-01

Discovery of antimicrobial peptides (AMP) is to a large extent based on screening of fractions of natural samples in bacterial growth inhibition assays. However, the use of bacteria is not limited to screening for antimicrobial substances. In later steps, bioengineered "bugs" can be applied to both production and characterization of AMPs. Here we describe the idea to use genetically modified Escherichia coli strains for both these purposes. This approach allowed us to investigate SpStrongylocins 1 and 2 from the purple sea urchin Strongylocentrotus purpuratus only based on sequence information from a cDNA library and without previous direct isolation or chemical synthesis of these peptides. The recombinant peptides are proved active against all bacterial strains tested. An assay based on a recombinant E. coli sensor strain expressing insect luciferase, revealed that SpStrongylocins are not interfering with membrane integrity and are therefore likely to have intracellular targets. © 2010 Landes Bioscience

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

NASA Astrophysics Data System (ADS)

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

2016-06-01

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

Essential oil of the leaves of Ricinus communis L.: in vitro cytotoxicity and antimicrobial properties.

PubMed

Zarai, Zied; Ben Chobba, Ines; Ben Mansour, Riadh; Békir, Ahmed; Gharsallah, Néji; Kadri, Adel

2012-08-13

The aim of the present study was to appraise the antimicrobial activity of Ricinus communis L. essential oil against different pathogenic microorganisms and the cytotoxic activity against HeLa cell lines. The agar disk diffusion method was used to study the antibacterial activity of Ricinus communis L. essential oil against 12 bacterial and 4 fungi strains. The disc diameters of zone of inhibition (DD), the minimum inhibitory concentrations (MIC) and the concentration inhibiting 50% (IC50) were investigated to characterize the antimicrobial activities of this essential oil. The in vitro cytotoxicity of Ricinus communis L. essential oil was examined using a modified MTT assay; the viability and the IC50 were used to evaluate this test. The essential oil from the leaves of Ricinus communis L. was analyzed by GC-MS and bioassays were carried out. Five constituents of the oil were identified by GC-MS. The antimicrobial activity of the oil was investigated in order to evaluate its efficacy against twelve bacteria and four fungi species, using disc diffusion and minimum inhibitory concentration methods. The essential oil showed strong antimicrobial activity against all microorganisms tested with higher sensitivity for Bacillus subtilis, Staphylococcus aureus and Enterobacter cloacae. The cytotoxic and apoptotic effects of the essential oil on HeLa cell lines were examined by MTT assay. The cytotoxicity of the oil was quite strong with IC50 values less than 2.63 mg/ml for both cell lines. The present study showed the potential antimicrobial and anticarcinogenic properties of the essential oil of Ricinus communis L., indicating the possibilities of its potential use in the formula of natural remedies for the topical treatment of infections.

Synthesis and characterization of a metal complex containing naringin and Cu, and its antioxidant, antimicrobial, antiinflammatory and tumor cell cytotoxicity.

PubMed

Pereira, Regina M S; Andrades, Norma E D; Paulino, Niraldo; Sawaya, Alexandra C H F; Eberlin, Marcos N; Marcucci, Maria C; Favero, Giovani Marino; Novak, Estela Maria; Bydlowski, Sérgio Paulo

2007-07-09

The antioxidant activity of flavonoids is believed to increase when they are coordinated with transition metal ions. However, the literature on this subject is contradictory and the outcome seems to largely depend on the experimental conditions. In order to understand the contribution of the metal coordination and the type of interaction between a flavonoid and the metal ion, in this study a new metal complex of Cu (II) with naringin was synthesized and characterized by FT-IR, UV-VIS, mass spectrometry (ESI-MS/MS), elemental analysis and 1H-NMR. The results of these analyses indicate that the complex has a Cu (II) ion coordinated via positions 4 and 5 of the flavonoid. The antioxidant, anti-inflammatory and antimicrobial activities of this complex were studied and compared with the activity of free naringin. The Naringin-Cu (II) complex 1 showed higher antioxidant, anti-inflammatory and tumor cell cytotoxicity activities than free naringin without reducing cell viability.

Antagonistic intestinal microflora produces antimicrobial substance inhibitory to Pseudomonas species and other spoilage organisms.

PubMed

Hatew, Bayissa; Delessa, Tenagne; Zakin, Vered; Gollop, Natan

2011-10-01

Chicken intestine harbors a vast number of bacterial strains. In the present study, antimicrobial substance produced by lactic acid bacteria (LAB) isolated from the gastrointestinal tract of healthy chicken was detected, characterized, and purified. Based on 16S rRNA sequencing, the bacteria were identified as Lactobacillus plantarum vN. The antimicrobial substance produced by this bacterium was designated vN-1 and exhibited a broad-spectrum of activity against many important pathogenic and spoilage microorganisms, including Pseudomonas aeruginosa, Staphylococcus aureus, Micrococcus luteus, Salmonella Typhimurium, and Erwinia amylovova. vN-1 was determined to be thermostable, insensitive to pH values ranging from 2.0 to 8.0, resistant to various organic solvents and to enzymatic inactivation. The inhibition kinetics displayed a bactericidal mode of action. This study revealed an antimicrobial substance with low molecular mass of less than 1 kDa as determined by ultrafiltration and having features not previously reported for LAB isolated from chicken intestines. The detection of this antimicrobial substance addresses an important aspect of biotechnological control agents of spoilage caused by Pseudomonas spp. and promises the possibility for preservation of refrigerated poultry meat. Practical Application:  The newly characterized antimicrobial substance and designated as vN-1 may have the potential to be used in food preservation. © 2011 Institute of Food Technologists®

Characterization of the Antimicrobial Peptide Penisin, a Class Ia Novel Lantibiotic from Paenibacillus sp. Strain A3

PubMed Central

Baindara, Piyush; Chaudhry, Vasvi; Mittal, Garima; Liao, Luciano M.; Matos, Carolina O.; Khatri, Neeraj; Franco, Octavio L.; Patil, Prabhu B.

2015-01-01

Attempts to isolate novel antimicrobial peptides from microbial sources have been on the rise recently, despite their low efficacy in therapeutic applications. Here, we report identification and characterization of a new efficient antimicrobial peptide from a bacterial strain designated A3 that exhibited highest identity with Paenibacillus ehimensis. Upon purification and subsequent molecular characterization of the antimicrobial peptide, referred to as penisin, we found the peptide to be a bacteriocin-like peptide. Consistent with these results, RAST analysis of the entire genome sequence revealed the presence of a lantibiotic gene cluster containing genes necessary for synthesis and maturation of a lantibiotic. While circular dichroism and one-dimension nuclear magnetic resonance experiments confirmed a random coil structure of the peptide, similar to other known lantibiotics, additional biochemical evidence suggests posttranslational modifications of the core peptide yield six thioether cross-links. The deduced amino acid sequence of the putative biosynthetic gene penA showed approximately 74% similarity with elgicin A and 50% similarity with the lantibiotic paenicidin A. Penisin effectively killed methicillin-resistant Staphylococcus aureus (MRSA) and did not exhibit hemolysis activity. Unlike other lantibiotics, it effectively inhibited the growth of Gram-negative bacteria. Furthermore, 80 mg/kg of body weight of penisin significantly reduced bacterial burden in a mouse thigh infection model and protected BALB/c mice in a bacteremia model entailing infection with Staphylococcus aureus MTCC 96, suggesting that it could be a promising new antimicrobial peptide. PMID:26574006

Synthesis, Characterization and Biological Evaluation of Some Quinoxaline Derivatives: A Promising and Potent New Class of Antitumor and Antimicrobial Agents.

PubMed

Al-Marhabi, Aisha R; Abbas, Hebat-Allah S; Ammar, Yousry A

2015-11-03

In continuation of our endeavor towards the development of potent and effective anticancer and antimicrobial agents; the present work deals with the synthesis of some novel tetrazolo[1,5-a]quinoxalines, N-pyrazoloquinoxalines, the corresponding Schiff bases, 1,2,4-triazinoquinoxalines and 1,2,4-triazoloquinoxalines. These compounds were synthesized via the reaction of the key intermediate hydrazinoquinoxalines with various reagents and evaluated for anticancer and antimicrobial activity. The results indicated that tetrazolo[1,5-a]quinoxaline derivatives showed the best result, with the highest inhibitory effects towards the three tested tumor cell lines, which were higher than that of the reference doxorubicin and these compounds were non-cytotoxic to normal cells (IC50 values > 100 μg/mL). Also, most of synthesized compounds exhibited the highest degrees of inhibition against the tested strains of Gram positive and negative bacteria, so tetrazolo[1,5-a]quinoxaline derivatives show dual activity as anticancer and antimicrobial agents.

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

PubMed

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.

Exposure of the grass shrimp, Palaemonetes pugio, to antimicrobial compounds affects associated Vibrio bacterial density and development of antibiotic resistance.

PubMed

DeLorenzo, M E; Brooker, J; Chung, K W; Kelly, M; Martinez, J; Moore, J G; Thomas, M

2016-04-01

Antimicrobial compounds are widespread, emerging contaminants in the aquatic environment and may threaten ecosystem and human health. This study characterized effects of antimicrobial compounds common to human and veterinary medicine, aquaculture, and consumer personal care products [erythromycin (ERY), sulfamethoxazole (SMX), oxytetracycline (OTC), and triclosan (TCS)] in the grass shrimp Palaemonetes pugio. The effects of antimicrobial treatments on grass shrimp mortality and lipid peroxidation activity were measured. The effects of antimicrobial treatments on the bacterial community of the shrimp were then assessed by measuring Vibrio density and testing bacterial isolates for antibiotic resistance. TCS (0.33 mg/L) increased shrimp mortality by 37% and increased lipid peroxidation activity by 63%. A mixture of 0.33 mg/L TCS and 60 mg/L SMX caused a 47% increase in shrimp mortality and an 88% increase in lipid peroxidation activity. Exposure to SMX (30 mg/L or 60 mg/L) alone and to a mixture of SMX/ERY/OTC did not significantly affect shrimp survival or lipid peroxidation activity. Shrimp exposure to 0.33 mg/L TCS increased Vibrio density 350% as compared to the control whereas SMX, the SMX/TCS mixture, and the mixture of SMX/ERY/OTC decreased Vibrio density 78-94%. Increased Vibrio antibiotic resistance was observed for all shrimp antimicrobial treatments except for the mixture of SMX/ERY/OTC. Approximately 87% of grass shrimp Vibrio isolates displayed resistance to TCS in the control treatment suggesting a high level of TCS resistance in environmental Vibrio populations. The presence of TCS in coastal waters may preferentially increase the resistance and abundance of pathogenic bacteria. These results indicate the need for further study into the potential interactions between antimicrobials, aquatic organisms, and associated bacterial communities. © 2014 Wiley Periodicals, Inc.

Polyphenol, antioxidant and antimicrobial potential of six different white and red wine grape processing leftovers.

PubMed

Trošt, Kajetan; Klančnik, Anja; Mozetič Vodopivec, Branka; Sternad Lemut, Melita; Jug Novšak, Katja; Raspor, Peter; Smole Možina, Sonja

2016-11-01

During winemaking, grape polyphenols are only partly extracted, and consequently unexploited. The main aim was to characterize the phenolic content of freeze-dried grape skin and seed (FDSS) extracts obtained from Slovenian and international grape varieties and to evaluate their antioxidant, antimicrobial and anti-adhesive activities. FDSS of six Vitis vinifera L. grapevine cultivars from Vipava Valley region (Slovenia) underwent extraction and sonification under different conditions. Flavonols were the predominant content of extracts from white 'Zelen' and 'Sauvignon Blanc' grape varieties, with strong antimicrobial activities against Gram-negative bacteria. 'Pinot Noir' FDSS extracted with 50% aqueous ethanol extraction produced a high phenolic content in the final extract, which was further associated with strong antioxidant and antimicrobial activities against all tested bacteria. Bacterial adhesion to stainless steel surfaces with minimal and maximal surface roughness was significantly inhibited (up to 60%) across a wide FDSS concentration range, with lower concentrations also effective with two types of stainless steel surfaces. FDSS extracts from winery by-products show interesting phenolic profiles that include flavonols, catechins, anthocyanins and hydroxycinnamic acids, with yields influenced by grapevine cultivar and extraction conditions. The antioxidant, antimicrobial and anti-adhesive activities of 50% aqueous ethanol 'Pinot Noir' FDSS extract reveals potential applications in food, pharmaceutical and cosmetic industries for these bioactive residues. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Antimicrobial and anti-inflammatory activity of switchgrass-derived extractives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Labbe, Nicole; Ownley, Bonnie H.; Gwinn, Kimberly D.

Switchgrass is an increasingly important biofuel crop, but knowledge of switchgrass fungal pathogens is not extensive. The purpose of this research was to identify the fungal pathogens that decrease crop yield of switchgrass grown in Tennessee and to investigate a potential sustainable disease management strategy from a value-added by-product of the switchgrass biofuel conversion process. The specific objectives were 1) to identify and characterize prevalent fungal pathogens of switchgrass in Tennessee, 2) assess switchgrass seed produced in the United States for seedborne fungal pathogens, and 3) evaluate switchgrass extractives for antimicrobial activity against plant pathogens.

Synthesis and In Vitro Antimicrobial Evaluation of New 1,3,4-Oxadiazoles Bearing 5-Chloro-2-methoxyphenyl Moiety

PubMed Central

Prasanna Kumar, Basavapatna N.; Mohana, Kikkeri N.; Mallesha, Lingappa; Harish, Kikkeri P.

2013-01-01

A series of new 1,3,4-oxadiazole derivatives, 4(a–h), containing 5-chloro-2-methoxy benzohydrazide moiety were synthesized by the reaction of 5-chloro-2-methoxybenzoate with different aromatic carboxylic acids. These newly synthesized compounds were characterized by FT-IR, 1H NMR, mass spectra, and also by elemental analysis. All the newly synthesized compounds were screened for their antibacterial and antifungal activities. Antimicrobial studies revealed that compounds 4c, 4f, and 4g showed significant activity against tested strains. PMID:25374693

Identification and characterization of a novel antimicrobial protein from the housefly Musca domestica.

PubMed

Guo, Guo; Tao, Ruyu; Li, Yan; Ma, Huiling; Xiu, Jiangfan; Fu, Ping; Wu, Jianwei

2017-08-26

Antimicrobial peptides/proteins are immune-related molecules that are widely distributed in bacteria, fungi, plants, invertebrates and higher animals. They have exhibited great potential to be developed into antimicrobial drugs. The housefly, Musca domestica, lives in a highly contaminated environment and has adapted a robust immune system against various pathogens. As an effort to search for new antimicrobial molecules in the housefly, we investigated the function of an uncharacterized gene firstly by confirming that its expression was induced by infection in M. domestica. The corresponding protein was then shown to have potent antimicrobial activity. Scanning Electron Microscopy data showed that treatment of C. albicans cells with the protein caused cell size decreasing and cell elongation. The results here suggest the protein a novel class of antimicrobial protein and provide new insights into the immunological mechanisms by which M. domestica combats invading C. albicans. Copyright © 2017 Elsevier Inc. All rights reserved.

Antimicrobial action of an endophytic fungi from Sophor flavescens and structure identification of its active constituent

PubMed Central

Yu, Na; He, Lu; Liu, Na; Wang, Yong; Xu, Hongbo; Liu, Dandan

2014-01-01

Endophytic fungus BS002 was isolated and characterized from Sophora flavescens by plate method, which has broad antimicrobial activity. Isolation and trace of a new bioactive compound from the fungus’ culture extracts with the method of column chromatography and TLC biological autoradiography was conducted. Finally, it was identified as 6,7-(2′E) dibutenyl-5,8-dihydroxy-(Z)-cyclooct-2-ene-1,4-dione by nuclear magnetic resonance, infrared and liquid chromatography–mass spectrometry. The compound presented strong antifungal activities for example: Botryosphaeria berengriana f.sp. piricola, Physalospora piricola, Cladosporium cucumerinum Ell. Arthur., Fusarium oxysporum f.sp. cucumerinum, Fusarium moniliforme. The inhibition to Physalospora piricola was the strongest with an antibacterial diameter of 45 mm. This paper is the first report of the antimicrobial activity of endophytic fungi BS002 that was the secondary metabolites extracted from the seeds of Sophora flavescens. The results provide a broad foreground for biopharmaceuticals and biopesticide. PMID:26019517

Chitosan derivatives targeting lipid bilayers: Synthesis, biological activity and interaction with model membranes.

PubMed

Martins, Danubia Batista; Nasário, Fábio Domingues; Silva-Gonçalves, Laiz Costa; de Oliveira Tiera, Vera Aparecida; Arcisio-Miranda, Manoel; Tiera, Marcio José; Dos Santos Cabrera, Marcia Perez

2018-02-01

The antimicrobial activity of chitosan and derivatives to human and plant pathogens represents a high-valued prospective market. Presently, two low molecular weight derivatives, endowed with hydrophobic and cationic character at different ratios were synthesized and characterized. They exhibit antimicrobial activity and increased performance in relation to the intermediate and starting compounds. However, just the derivative with higher cationic character showed cytotoxicity towards human cervical carcinoma cells. Considering cell membranes as targets, the mode of action was investigated through the interaction with model lipid vesicles mimicking bacterial, tumoral and erythrocyte membranes. Intense lytic activity and binding are demonstrated for both derivatives in anionic bilayers. The less charged compound exhibits slightly improved selectivity towards bacterial model membranes, suggesting that balancing its hydrophobic/hydrophilic character may improve efficiency. Observing the aggregation of vesicles, we hypothesize that the "charge cluster mechanism", ascribed to some antimicrobial peptides, could be applied to these chitosan derivatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antimicrobial, antioxidant and cytotoxic properties of essential oil from Dictamnus angustifolius.

PubMed

Sun, Jianbo; Wang, Xinzhi; Wang, Pei; Li, Linzhen; Qu, Wei; Liang, Jingyu

2015-01-15

Dictamnus angustifolius (Rutaceae) has been used as an alternative for folk medicine, Dictamnus dasycarpus in the treatment of rheumatism, bleeding, itching, jaundice, chronic hepatitis, and skin diseases in Xinjiang Province of China. The aim of this study was to evaluate the antimicrobial and antioxidant activities of essential oil (EO) from Dictamnus angustifolius, correlated with their chemical composition and evaluate their cytotoxicity. The EO were extracted by water-distillation using a Clevenger-type apparatus. The chemical composition of EO was identified by GC-MS analysis. The antimicrobial activity was evaluated against five microorganisms by the agar disc diffusion method and minimal inhibitory concentration (MIC) assay. The antioxidant activity was measured by employing DPPH and FRAP assays. The cytotoxic activity was evaluated in the mammalian cells lines A549, MCF7, B16 and LoVo using the MTT method to assess cell viability. 52 compounds representing the 97.2% of the total oil were identified by GC/MS. The major constituents of the oil were tetramethylenecyclobutane (42.07%) and fraxinellone (19.06%). The antimicrobial activity showed that the EO possess significant inhibition in Monilia albican ATCC 10231 and Staphylococcus aureus ATCC 6538. The antioxidant activity suggested that the EO possess significant reducing power. The cytotoxic activity of the EO in MCF7 and LoVo cells was significant stronger than in the other cell lines. This study is the first characterization of the chemical composition and biological activities of EO from Dictamnus angustifolius. All experimental data indicate that the EO have not only remarkable antioxidant properties but also potential antimicrobial activity and cytotoxic activities. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Adenylate Kinase Release as a High-Throughput-Screening-Compatible Reporter of Bacterial Lysis for Identification of Antibacterial Agents

PubMed Central

Jacobs, Anna C.; DiDone, Louis; Jobson, Jennielle; Sofia, Madeline K.

2013-01-01

Adenylate kinase (AK) is a ubiquitous intracellular enzyme that is released into the extracellular space upon cell lysis. We have shown that AK release serves as a useful reporter of bactericidal agent activity and can be exploited for antimicrobial screening purposes. The AK assay exhibits improved sensitivity over that of growth-based assays and can detect agents that are active against bacteria in clinically relevant growth states that are difficult to screen using conventional approaches, such as small colony variants (SCV) and bacteria within established biofilms. The usefulness of the AK assay was validated by screening a library of off-patent drugs for agents that exhibit antimicrobial properties toward a variety of bacterial species, including Escherichia coli and all members of the “ESKAPE” pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species). The assay detected antibiotics within the library that were expected to be active against the organism screened. Moreover, 38 drugs with no previously reported antibacterial activity elicited AK release. Four of these were acquired, and all were verified to exhibit antimicrobial activity by standard susceptibility testing. Two of these molecules were further characterized. The antihistamine, terfenadine, was active against S. aureus planktonic, SCV population, and biofilm-associated cells. Tamoxifen, an estrogen receptor antagonist, was active toward E. faecium in vitro and also reduced E. faecium pathogenesis in a Galleria mellonella infection model. Our data demonstrate that the AK assay provides an attractive screening approach for identifying new antimicrobial agents. Further, terfenadine and tamoxifen may represent novel antimicrobial drug development scaffolds. PMID:23027196

Diorganotin(IV) complexes of biologically potent 4(3H)-quinazolinone derived Schiff bases: synthesis, spectroscopic characterization, DNA interaction studies and antimicrobial activity.

PubMed

Prasad, Kollur Shiva; Kumar, Linganna Shiva; Chandan, Shivamallu; Jayalakshmi, Basvegowda; Revanasiddappa, Hosakere D

2011-10-15

Four Schiff base ligands and their corresponding organotin(IV) complexes have been synthesized and characterized by elemental analyses, IR, (1)H NMR, MS and thermal studies. The Schiff bases are obtained by the condensation of 3-amino-2-methyl-4(3H)-quinazolinone with different substituted aldehydes. The elemental analysis data suggest the stoichiometry to be 1:1 ratio formation. Infrared spectral data agreed with the coordination to the central metal ion through imine nitrogen, lactam oxygen and deprotonated phenolic oxygen atoms. All the synthesized compounds have been evaluated for antimicrobial activity against selected species of microorganisms. In addition, DNA binding/cleavage capacity of the compounds was analyzed by absorption spectroscopy, viscosity measurements and gel electrophoresis methods. Copyright © 2011 Elsevier B.V. All rights reserved.

Design, synthesis and characterization of macrocyclic ligand based transition metal complexes of Ni(II), Cu(II) and Co(II) with their antimicrobial and antioxidant evaluation

NASA Astrophysics Data System (ADS)

Gull, Parveez; Malik, Manzoor Ahmad; Dar, Ovas Ahmad; Hashmi, Athar Adil

2017-04-01

Three new complexes Ni(II), Cu(II) and Co(II) were synthesized of macrocyclic ligand derived from 1, 4-dicarbonyl-phenyl-dihydrazide and O-phthalaldehyde in the ratio of 2:2. The synthesized compounds were characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, FTIR, UV-Vis., Mass and 1H NMR spectral studies. The electronic spectra of the metal complexes indicate a six coordinate octahedral geometry of the central metal ion. These metal complexes and the ligand were evaluated for antimicrobial activity against bacteria (E. coli, B. subtilis, S. aureus) and fungi (A. niger, A. flavus, C. albicans) and compared against standard drugs chloramphenicol and nystatin respectively. In addition, the antioxidant activity of the compounds was also investigated through scavenging effect on DPPH radicals.

A broad-spectrum antimicrobial activity of Bacillus subtilis RLID 12.1.

PubMed

Ramachandran, Ramya; Chalasani, Ajay Ghosh; Lal, Ram; Roy, Utpal

2014-01-01

In the present study, an attempt was made to biochemically characterize the antimicrobial substance from the soil isolate designated as RLID 12.1 and explore its potential applications in biocontrol of drug-resistant pathogens. The antimicrobial potential of the wild-type isolate belonging to the genus Bacillus was determined by the cut-well agar assay. The production of antimicrobial compound was recorded maximum at late exponential growth phase. The ultrafiltered concentrate was insensitive to organic solvents, metal salts, surfactants, and proteolytic and nonproteolytic enzymes. The concentrate was highly heat stable and active over a wide range of pH values. Partial purification, zymogram analysis, and TLC were performed to determine the preliminary biochemical nature. The molecular weight of the antimicrobial peptide was determined to be less than 2.5 kDa in 15% SDS-PAGE and in zymogram analysis against Streptococcus pyogenes. The N-terminal amino acid sequence by Edman degradation was partially determined to be T-P-P-Q-S-X-L-X-X-G, which shows very insignificant identity to other antimicrobial peptides from bacteria. The minimum inhibitory concentrations of dialysed and partially purified ion exchange fractions were determined against some selected gram-positive and gram-negative bacteria and some pathogenic yeasts. The presence of three important antimicrobial peptide biosynthesis genes ituc, fend, and bmyb was determined by PCR.

Conventional and microwave-assisted synthesis of new indole-tethered benzimidazole-based 1,2,3-triazoles and evaluation of their antimycobacterial, antioxidant and antimicrobial activities.

PubMed

Ashok, Dongamanti; Gundu, Srinivas; Aamate, Vikas Kumar; Devulapally, Mohan Gandhi

2018-04-18

A new series of triheterocycles containing indole-benzimidazole-based 1,2,3-triazole hybrids have been synthesized in good yields via a microwave-assisted click reaction. All the compounds were characterized by IR, [Formula: see text] NMR, [Formula: see text] NMR and mass spectroscopy and were evaluated for their in vitro antitubercular activity against the Mycobacterium tuberculosis H37Rv strain. Compounds 4b, 4h and 4i displayed highly potent antitubercular activity with MIC 3.125-6.25 [Formula: see text]. The antioxidant potential was evaluated using 2,2-diphenyl-1-picryl hydrazine and [Formula: see text] radical scavenging activity, and compounds 4e,4f and 4g showed excellent radical scavenging activity with [Formula: see text] values in the range of 08.50-10.05 [Formula: see text]. Furthermore, the compounds were evaluated for antimicrobial activity against numerous bacterial and fungal strains, and compounds 4b, 4c and 4h were found to be the most promising potential antimicrobial molecules with MIC 3.125-6.25 [Formula: see text].

Modeling with the logistic regression of the growth/no growth interface of Saccharomyces cerevisiae in relation to 2 antimicrobial terpenes (citral and linalool), pH, and a(w).

PubMed

Tabanelli, Giulia; Montanari, Chiara; Patrignani, Francesca; Siroli, Lorenzo; Lanciotti, Rosalba; Gardini, Fausto

2014-03-01

The antimicrobial effects of 2 terpenes (citral and linalool) on a Saccharomyces cerevisiae strain isolated from spoiled soft drink have been evaluated, alone or in combination, in relation to pH and aw using in vitro assays. The obtained data were fitted with the logit model to find the growth/no growth boundary regions of the 2 terpenes, focusing the attention on the type of interaction exerted by citral and linalool. In particular, the results showed an increase of citral antimicrobial effect in growth media characterized by low aw value, as well as a higher linalool antimicrobial effect in media at low pH. Moreover, the interactive effects of the 2 terpenes were exploited. The results obtained with the model were validated in an independent experiment. The knowledge of the interactions of essential oil molecules with enhanced antimicrobial activity, in relation to some of the most important chemicophysical variables, can have important industrial applications, since these substances are able to assure the desired antimicrobial effect without negatively modifying the product flavor profile. The effects of the main chemicophysical parameters (such as aw and pH) on the antimicrobial activity of bioactive terpenes are necessary for the definition of an industrially applicable preservation strategy based on the use of essential oils as natural antimicrobials aimed to prolong shelf life of food products. © 2014 Institute of Food Technologists®

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

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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.

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

PubMed Central

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

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. PMID:29410826

Isolation and characterization of antimicrobial food components.

PubMed

Papetti, Adele

2012-04-01

Nowadays there is an evident growing interest in natural antimicrobial compounds isolated from food matrices. According to the type of matrix, different isolation and purification steps are needed and as these active compounds belong to different chemical classes, also different chromatographic and electrophoretic methods coupled with various detectors (the most used diode array detector and mass spectrometer) have to be performed. This review covers recent steps made in the fundamental understanding of sample preparation methods as well as of analytical tools useful for the complete characterization of bioactive food compounds. The most commonly used methods for extraction of natural antimicrobial compounds are the conventional liquid-liquid or solid-liquid extraction and the modern techniques such as pressurized liquid extraction, microwave-assisted extraction, ultrasound-assisted extraction, solid-phase micro-extraction, supercritical fluid extraction, and matrix solid phase dispersion. The complete characterization of the compounds is achieved using both monodimensional chromatographic processes (LC, nano-LC, GC, and CE coupled with different type of detectors) and, recently, using comprehensive two-dimensional systems (LC×LC and GC×GC). Copyright © 2011 Elsevier Ltd. All rights reserved.

Enzyme-mediated formulation of stable elliptical silver nanoparticles tested against clinical pathogens and MDR bacteria and development of antimicrobial surgical thread.

PubMed

Thapa, Rupak; Bhagat, Chintan; Shrestha, Pragya; Awal, Suvash; Dudhagara, Pravin

2017-05-16

Silver nanoparticles (AgNPs) are believed to be emerging tool against various infectious diseases including multi-drug resistant (MDR) bacteria. In the present study, in vitro synthesis of AgNPs was optimized using 1:50 ratio of macerozyme (25 μg/μl) and 1 mM AgNO 3 incubated at 80 °C for 8 h. AgNPs were characterized by UV-Visible spectroscopy, dynamic light scattering (DLS), scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD). Characterization studies suggest the synthesis of elliptical, stable and crystalline AgNPs with an average size of 38.26 ± 0.4 nm calculated using TEM. The XRD pattern revealed the face-centered-cubic (fcc) form of metallic silver. Good shape integrity and dispersion of AgNPs after 1 year of incubation confirmed their stability. AgNPs were exibited the antimicrobial property against ten pathogenic bacteria, three molds and one yeast. The AgNPs also revealed remarkable antimicrobial activity against three MDR strains i.e. Extended spectrum beta-lactamase positive Escherichia coli, Staphylococcus aureus (MRSA) and Teicoplanin resistant Streptococcus Pneumoniae. The AgNPs coated surgical threads (suture) were revealed the remarkble antibacterial activity against three MDR strains. This is the first report to synthesize antimicrobial elliptical AgNPs using enzymes. The results suggest the possibilities to develop the nanoparticles coated antimicrobial medical fabric to combat against MDR infection.

Palladium(II) and platinum(II) derivatives of benzothiazoline ligands: Synthesis, characterization, antimicrobial and antispermatogenic activity

NASA Astrophysics Data System (ADS)

Sharma, Krishna; Singh, R. V.; Fahmi, Nighat

2011-01-01

A series of Pd(II) and Pt(II) complexes with two N ∩S donor ligands, 5-chloro-3-(indolin-2-one)benzothiazoline and 6-nitro-3-(indolin-2-one)benzothiazoline, have been synthesized by the reaction of metal chlorides (PdCl 2 and PtCl 2) with ligands in 1:2 molar ratios. All the synthesized compounds were characterized by elemental analyses, melting point determinations and a combination of electronic, IR, 1H NMR and 13C NMR spectroscopic techniques for structure elucidation. In order to evaluate the effect of metal ions upon chelation, both the ligands and their complexes have been screened for their antimicrobial activity against the various pathogenic bacterial and fungal strains. The metal complexes have shown to be more antimicrobial against the microbial species as compared to free ligands. One of the ligands, 5-chloro-3-(indolin-2-one)benzothiazoline and its corresponding palladium and platinum complexes have been tested for their antifertility activity in male albino rats. The marked reduction in sperm motility and density resulted in infertility by 62-90%. Significant alterations were found in biochemical parameters of reproductive organs in treated animals as compared to control group. It is concluded that all these effects may finally impair the fertility of male rats.

Synthesis, characterization, antimicrobial screening and computational studies of 4-[3-(4-methoxy-phenyl)-allylideneamino]-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-one

NASA Astrophysics Data System (ADS)

Obasi, L. N.; Kaior, G. U.; Rhyman, L.; Alswaidan, Ibrahim A.; Fun, Hoong-Kun; Ramasami, P.

2016-09-01

The Schiff base, 4-[3-(4-methoxy-phenyl)-allylideneamino]-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-one (TPMC/AAP) was synthesized by the condensation of 4-aminoantipyrine (4-amino-1,5-dimethyl-2-phenylpyrazole-3-one) and trans-para-methoxycinnamaldehyde (trans-3,4-methoxyphenyl-2-propenal) in dry methanol at 75 °C. The compound was characterized using elemental microanalysis, IR, NMR, UV spectroscopies and single-crystal X-ray crystallography. The X-ray structure determination shows that the Schiff base, (TPMC/AAP) is orthorhombic with the Pbca space group. The anti-microbial screening of the compound was carried out with Escherichia coli, Bacillus subtillis, Staphylococcus aureus, Pseudemonas aeruginosa, Candida albicans and Aspergillus niger using agar well diffusion method. The Schiff base possesses significant antimicrobial activity. The minimum inhibitory concentration (MIC) of the compound was also determined and the activity was compared with that of conventional drugs ciprofloxacin and ketoconazole. The compound (TPMC/AAP) showed varying activity against the cultured bacteria and fungi used. To complement the experimental data, density functional theory (DFT) was used to have deeper understanding into the molecular parameters and infrared spectra of the compound.

Phyto-mediated metallic nano-architectures via Melissa officinalis L.: synthesis, characterization and biological properties.

PubMed

Fierascu, Irina; Georgiev, Milen I; Ortan, Alina; Fierascu, Radu Claudiu; Avramescu, Sorin Marius; Ionescu, Daniela; Sutan, Anca; Brinzan, Alexandru; Ditu, Lia Mara

2017-09-29

The development of methods for obtaining new materials with antimicrobial properties, based on green chemistry principles has been a target of research over the past few years. The present paper describes the phyto-mediated synthesis of metallic nano-architectures (gold and silver) via an ethanolic extract of Melissa officinalis L. (obtained by accelerated solvent extraction). Different analytic methods were applied for the evaluation of the extract composition, as well as for the characterization of the phyto-synthesized materials. The cytogenotoxicity of the synthesized materials was evaluated by Allium cepa assay, while the antimicrobial activity was examined by applying both qualitative and quantitative methods. The results demonstrate the synthesis of silver nanoparticles (average diameter 13 nm) and gold nanoparticles (diameter of ca. 10 nm); the bi-metallic nanoparticles proved to have a core-shell flower-like structure, composed of smaller particles (ca. 8 nm). The Ag nanoparticles were found not active on nuclear DNA damage. The Au nanoparticles appeared nucleoprotective, but were aggressive in generating clastogenic aberrations in A. cepa root meristematic cells. Results of the antimicrobial assays show that silver nanoparticles were active against most of the tested strains, as the lowest MIC value being obtained against B. cereus (approx. 0.0015 mM).

Preparation, characterization and antimicrobial efficiency of Ag/PDDA-diatomite nanocomposite.

PubMed

Panáček, Aleš; Balzerová, Anna; Prucek, Robert; Ranc, Václav; Večeřová, Renata; Husičková, Vendula; Pechoušek, Jiří; Filip, Jan; Zbořil, Radek; Kvítek, Libor

2013-10-01

Nanocomposites consisting of diatomaceous earth particles and silver nanoparticles (silver NPs) with high antimicrobial activity were prepared and characterized. For the purpose of nanocomposite preparation, silver NPs with an average size of 28nm prepared by modified Tollens process were used. Nanocomposites were prepared using poly(diallyldimethylammonium) chloride (PDDA) as an interlayer substance between diatomite and silver NPs which enables to change diatomite original negative surface charge to positive one. Due to strong electrostatic interactions between negatively charged silver NPs and positively charged PDDA-modified diatomite, Ag/PDDA-diatomite nanocomposites with a high content of silver (as high as 46.6mgAg/1g of diatomite) were prepared. Because of minimal release of silver NPs from prepared nanocomposites to aqueous media (<0.3mg Ag/1g of nanocomposite), the developed nanocomposites are regarded as a potential useful antimicrobial material with a long-term efficiency showing no risk to human health or environment. All the prepared nanocomposites exhibit a high bactericidal activity against Gram-negative and Gram-positive bacteria and fungicidal activity against yeasts at very low concentrations as low as 0.11g/L, corresponding to silver concentration of 5mg/L. Hence, the prepared nanocomposites constitute a promising candidate suitable for the microbial water treatment in environmental applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Identification, Characterization, Immunolocalization, and Biological Activity of Lucilin Peptide.

PubMed

Alberto, Tellez German; Alejandra, Zapata Jesica; Johanna, Toro Lily; Carolina, Henao Diana; Pablo, Bedoya Juan; David, Rivera Juan; Valentin, Trujillo Juan; Bruno, Rivas; Lopez, Richard Onalbi Hoyos; Carlos, Castano Jhon

2018-06-08

Maggots from the Lucilia sp. genus are used for debridement of infected and necrotic wounds. Broad-spectrum antimicrobial activity has been described in the excretion/secretions (ES 1 ) of these larvae. This study identifies the genetic sequence of a cecropin-like antimicrobial peptide from Lucilia eximia. Total RNA was extracted and used for PCR-RACE amplification of a cecropin, the native peptide was immunolocalized in the tissues and secretions of the larvae, and a synthetic analog was used to explore its antimicrobial, cytotoxic, LPS neutralizing and wound-healing activities in vitro. The genetic cDNA sequence of a cecropin-like antimicrobial peptide in L. eximia called "Lucilin" was amplified, corresponding to 63 aa completed protein and 40 aa mature peptide; the structure of the mature peptide was predicted as an α-helix. The peptide was immunolocalized in the salivary glands, fat body, the ES, and hemolymph of the maggots. Lucilin synthetic peptide analog was active against E. coli DH10B with a MIC 2 of 7.8 µg/mL, E. coli extended spectrum b-lactamase (ESBL) (MIC: 15.6 µg/mL), and Enterobacter cloacae (MIC: 125 µg/mL), but it was not active against Pseudomonas aeruginosa and Staphylococcus epidermidis; and had no cytotoxic or hemolytic activity. It showed immunomodulatory activity against human peripheral blood mononuclear cells (PBMCs) stimulated with LPS, reducing the TNF-α production when treated at 17 µg/mL and induces cell migration of Hacat at 5 and 50 µg/mL. Lucilin is a cecropin-like peptide from L. eximia with antimicrobial activity against Gram negative bacteria and immunomodulatory activities, decreasing the TNF-α production in PBMCs and inducing cellular migration in human keratinocytes. Copyright © 2018. Published by Elsevier B.V.

Antimicrobial activity of the essential oil from Lippia sidoides, carvacrol and thymol against oral pathogens.

PubMed

Botelho, M A; Nogueira, N A P; Bastos, G M; Fonseca, S G C; Lemos, T L G; Matos, F J A; Montenegro, D; Heukelbach, J; Rao, V S; Brito, G A C

2007-03-01

Dental caries and periodontal disease are associated with oral pathogens. Several plant derivatives have been evaluated with respect to their antimicrobial effects against such pathogenic microorganisms. Lippia sidoides Cham (Verbenaceae), popularly known as "Alecrim-pimenta" is a typical shrub commonly found in the Northeast of Brazil. Many plant species belonging to the genus Lippia yield very fragrant essential oils of potential economic value which are used by the industry for the commercial production of perfumes, creams, lotions, and deodorants. Since the leaves of L. sidoides are also extensively used in popular medicine for the treatment of skin wounds and cuts, the objective of the present study was to evaluate the composition and antimicrobial activity of L. sidoides essential oil. The essential oil was obtained by hydro-distillation and analyzed by GC-MS. Twelve compounds were characterized, having as major constituents thymol (56.7%) and carvacrol (16.7%). The antimicrobial activity of the oil and the major components was tested against cariogenic bacterial species of the genus Streptococcus as well as Candida albicans using the broth dilution and disk diffusion assays. The essential oil and its major components thymol and carvacrol exhibited potent antimicrobial activity against the organisms tested with minimum inhibitory concentrations ranging from 0.625 to 10.0 mg/mL. The most sensitive microorganisms were C. albicans and Streptococcus mutans. The essential oil of L. sidoides and its major components exert promising antimicrobial effects against oral pathogens and suggest its likely usefulness to combat oral microbial growth.

Antimicrobial activity of organotin(IV) complexes with the ligand benzil bis(benzoylhydrazone) and 4,4'-bipyridyl as coligand.

PubMed

López-Torres, Elena; Zani, Franca; Mendiola, M Antonia

2011-05-01

Several methyltin(IV) and butyltin(IV) complexes with the ligand benzil bis(benzoylhydrazone) and 4,4'-bipyridyl as coligand were synthesised and characterized by elemental analysis and by IR, (1)H, (13)C and (119)Sn NMR spectroscopies. Some of them were also analyzed using single crystal X-ray diffraction. The title compounds were evaluated for their in vitro antimicrobial properties. All buthyltin complexes showed significant inhibition of Gram positive bacteria, resulting Bacillus subtilis, Sarcina lutea and both methicillin-susceptible and methicillin-resistant Staphylococcus epidermidis the most sensitive strains. Furthermore, they were able to inhibit the growth of Gram negative bacteria, especially Proteus vulgaris, whereas no activity was exhibited against fungi. All methyltin complexes were devoid of antimicrobial properties. Copyright © 2011 Elsevier Inc. All rights reserved.

Synthesis, X-ray diffraction method, spectroscopic characterization (FT-IR, 1H and 13C NMR), antimicrobial activity, Hirshfeld surface analysis and DFT computations of novel sulfonamide derivatives

NASA Astrophysics Data System (ADS)

Demircioğlu, Zeynep; Özdemir, Fethi Ahmet; Dayan, Osman; Şerbetçi, Zafer; Özdemir, Namık

2018-06-01

Synthesized compounds of N-(2-aminophenyl)benzenesulfonamide 1 and (Z)-N-(2-((2-nitrobenzylidene)amino)phenyl)benzenesulfonamide 2 were characterized by antimicrobial activity, FT-IR, 1H and 13C NMR. Two new Schiff base ligands containing aromatic sulfonamide fragment of (Z)-N-(2-((3-nitrobenzylidene)amino)phenyl)benzenesulfonamide 3 and (Z)-N-(2-((4-nitrobenzylidene)amino)phenyl)benzenesulfonamide 4 were synthesized and investigated by spectroscopic techniques including 1H and 13C NMR, FT-IR, single crystal X-ray diffraction, Hirshfeld surface, theoretical method analyses and by antimicrobial activity. The molecular geometry obtained from the X-ray structure determination was optimized Density Functional Theory (DFT/B3LYP) method with the 6-311++G(d,p) basis set in ground state. From the optimized geometry of the molecules of 3 and 4, the geometric parameters, vibrational wavenumbers and chemical shifts were computed. The optimized geometry results, which were well represented the X-ray data, were shown that the chosen of DFT/B3LYP 6-311G++(d,p) was a successful choice. After a successful optimization, frontier molecular orbitals, chemical activity, non-linear optical properties (NLO), molecular electrostatic mep (MEP), Mulliken population method, natural population analysis (NPA) and natural bond orbital analysis (NBO), which cannot be obtained experimentally, were calculated and investigated.

Antimicrobial bacterial cellulose nanocomposites prepared by in situ polymerization of 2-aminoethyl methacrylate.

PubMed

Figueiredo, Ana R P; Figueiredo, Andrea G P R; Silva, Nuno H C S; Barros-Timmons, Ana; Almeida, Adelaide; Silvestre, Armando J D; Freire, Carmen S R

2015-06-05

Antimicrobial bacterial cellulose/poly(2-aminoethyl methacrylate) (BC/PAEM) nanocomposites were prepared by in situ radical polymerization of 2-aminoethyl methacrylate, using variable amounts of N,N-methylenebis(acrylamide) (MBA) as cross-linker. The obtained nanocomposites were characterized in terms of their structure, morphology, thermal stability, mechanical properties and antibacterial activity. The ensuing composite membranes were significantly more transparent than those of pure BC and showed improved thermal and mechanical properties. The antibacterial activity of the obtained nanocomposites was assessed towards a recombinant bioluminescent Escherichia coli and only the non-crosslinked nanocomposite (BC/PAEM) proved to have antibacterial activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Molecular Characterization and Antimicrobial Activity of an Endolichenic Fungus, Aspergillus sp. Isolated from Parmelia caperata of Similipal Biosphere Reserve, India.

PubMed

Padhi, Srichandan; Das, Devaranjan; Panja, Suraj; Tayung, Kumananda

2017-06-01

Endolichenic fungi are microbes that inhabit healthy inner lichen tissues without any disease symptoms. They have been reported to produce new and interesting bioactive metabolites. In the present study, an endolichenic fungus frequently isolated from surface-sterilized lichen thallus of Parmelia caperata has been described. The fungus was identified as Aspergillus tubingensis based on morphological traits and ITS rDNA sequence. Crude metabolites extracted from the culture broth exhibited considerable antimicrobial activity against a panel of clinically significant human pathogens. The fungus showed optimum antimicrobial activity in PDB medium in day 7 of incubation period. PDB medium amended with 1 % NaCl and at alkaline pH was found to be optimal for antimicrobial metabolites production. Enhanced activity was observed when the fungus was exposed briefly to a heat shock of 60 °C during incubation. The metabolites showed optimum λ-max at 214 nm with an absorbance value of 1.589. Molecular characterization of the isolate was carried out by ITS phylogeny and ITS2 secondary structure analyses. The phylogenetic trees based on both ITS rDNA and ITS2 sequences showed the isolate within the clade A. tubingensis. Considering the ubiquity and ambiguity in identifying Aspergillus species of different lifestyles, a method to differentiate pathogenic and endophytic Aspergillus at species level was developed using ITS2 secondary structure analysis. The results showed common folding pattern in the secondary structures with a helix and a 5' dangling end found to be highly conserved. Certain features in the secondary structure like multi-bulges and a symmetric interior loop were observed to be unique which distinguish our isolate from other A. tubingensis.

Purification, crystal structure and antimicrobial activity of phenazine-1-carboxamide produced by a growth-promoting biocontrol bacterium, Pseudomonas aeruginosa MML2212.

PubMed

Shanmugaiah, V; Mathivanan, N; Varghese, B

2010-02-01

To purify and characterize an antimicrobial compound produced by a biocontrol bacterium, Pseudomonas aeruginosa MML2212, and evaluate its activity against rice pathogens, Rhizoctonia solani and Xanthomonas oryzae pv. oryzae. Pseudomonas aeruginosa strain MML2212 isolated from the rice rhizosphere with wide-spectrum antimicrobial activity was cultured in Kings'B broth using a fermentor for 36 h. The extracellular metabolites were isolated from the fermented broth using ethyl acetate extraction and purified by two-step silica-gel column chromatography. Three fractions were separated, of which a major compound was obtained in pure state as yellow needles. It was crystallized after dissolving with chloroform followed by slow evaporation. It is odourless with a melting point of 220-222 degrees C. It was soluble in most of the organic solvents and poorly soluble in water. The molecular mass of purified compound was estimated as 223.3 by mass spectral analysis. Further, it was characterized by IR, (1)H and (13)C NMR spectral analyses. The crystal structure of the compound was elucidated for the first time by X-ray diffraction study and deposited in the Cambridge Crystallographic Data Centre (http://www.ccde.com.ac.uk) with the accession no. CCDC 617344. The crystal compound was undoubtedly identified as phenazine-1-carboxamide (PCN) with the empirical formula of C(13)H(9)N(3)O. As this is the first report on the crystal structure of PCN, it provides additional information to the structural chemistry. Furthermore, the present study reports the antimicrobial activity of purified PCN on major rice pathogens, R. solani and X. oryzae pv. oryzae. Therefore, the PCN can be developed as an ideal agrochemical candidate for the control of both sheath blight and bacterial leaf blight diseases of rice.

Characterization of antimicrobial lipopeptides produced by Bacillus sp. LM7 isolated from chungkookjang, a Korean traditional fermented soybean food.

PubMed

Lee, Mi-Hwa; Lee, Jiyeon; Nam, Young-Do; Lee, Jong Suk; Seo, Myung-Ji; Yi, Sung-Hun

2016-03-16

A wild-type microorganism exhibiting antimicrobial activities was isolated from the Korean traditional fermented soybean food Chungkookjang and identified as Bacillus sp. LM7. During its stationary growth phase, the microorganism secreted an antimicrobial substance, which we partially purified using a simple two-step procedure involving ammonium sulfate precipitation and heat treatment. The partially purified antimicrobial substance, Anti-LM7, was stable over a broad pH range (4.0-9.0) and at temperatures up to 80 °C for 30 min, and was resistant to most proteolytic enzymes and maintained its activity in 30% (v/v) organic solvents. Anti-LM7 inhibited the growth of a broad range of Gram-positive bacteria, including Bacillus cereus and Listeria monocytogenes, but it did not inhibit lactic acid bacteria such as Lactobacillus plantarum and Lactococcus lactis subsp. Lactis. Moreover, unlike commercially available nisin and polymyxin B, Anti-LM7 inhibited certain fungal strains. Lastly, liquid chromatography-mass spectrometry analysis of Anti-LM7 revealed that it contained eight lipopeptides belonging to two families: four bacillomycin D and four surfactin analogs. These Bacillus sp. LM7-produced heterogeneous lipopeptides exhibiting extremely high stability and a broad antimicrobial spectrum are likely to be closely related to the antimicrobial activity of Chungkookjang, and their identification presents an opportunity for application of the peptides in environmental bioremediation, pharmaceutical, cosmetic, and food industries. Copyright © 2015 Elsevier B.V. All rights reserved.

A New Method of Producing a Natural Antibacterial Peptide by Encapsulated Probiotics Internalized with Inulin Nanoparticles as Prebiotics.

PubMed

Cui, Lian-Hua; Yan, Chang-Guo; Li, Hui-Shan; Kim, Whee-Soo; Hong, Liang; Kang, Sang-Kee; Choi, Yun-Jaie; Cho, Chong-Su

2018-04-28

Synbiotics are a combination of probiotics and prebiotics, which lead to synergistic benefits in host welfare. Probiotics have been used as an alternative to antibiotics. Among the probiotics, Pediococcus acidilactici (PA) has shown excellent antimicrobial activity against Salmonella Gallinarum (SG) as a major poultry pathogen and has improved the production performances of animals. Inulin is widely used as a prebiotic for the improvement of animal health and growth. The main aim of this study is to investigate the effect of the antimicrobial activity of inulin nanoparticles (INs)-internalized PA encapsulated into alginate/chitosan/alginate (ACA) microcapsules (MCs) in future in vivo application. The prepared phthalyl INs (PINs) were characterized by DLS and FE-SEM. The contents of phthal groups in phthalyl inulin were estimated by ¹H-NMR measurement as 25.1 mol.-%. The sizes of the PINs measured by DLS were approximately 203 nm. Internalization into PA was confirmed by confocal microscopy and flow cytometry. Antimicrobial activity of PIN-internalized probiotics encapsulated into ACA MCs was measured by co-culture antimicrobial assays on SG. PIN-internalized probiotics had a higher antimicrobial ability than that of ACA MCs loaded with PA/inulin or PA. Interestingly, when PINs were treated with PA and encapsulated into ACA MCs, as a natural antimicrobial peptide, pediocin was produced much more in the culture medium compared with other groups inulin-loaded ACA MCs and PA-encapsulated into ACA MCs.

Genomewide Analysis of the Antimicrobial Peptides in Python bivittatus and Characterization of Cathelicidins with Potent Antimicrobial Activity and Low Cytotoxicity.

PubMed

Kim, Dayeong; Soundrarajan, Nagasundarapandian; Lee, Juyeon; Cho, Hye-Sun; Choi, Minkyeung; Cha, Se-Yeoun; Ahn, Byeongyong; Jeon, Hyoim; Le, Minh Thong; Song, Hyuk; Kim, Jin-Hoi; Park, Chankyu

2017-09-01

In this study, we sought to identify novel antimicrobial peptides (AMPs) in Python bivittatus through bioinformatic analyses of publicly available genome information and experimental validation. In our analysis of the python genome, we identified 29 AMP-related candidate sequences. Of these, we selected five cathelicidin-like sequences and subjected them to further in silico analyses. The results showed that these sequences likely have antimicrobial activity. The sequences were named Pb-CATH1 to Pb-CATH5 according to their sequence similarity to previously reported snake cathelicidins. We predicted their molecular structure and then chemically synthesized the mature peptide for three putative cathelicidins and subjected them to biological activity tests. Interestingly, all three peptides showed potent antimicrobial effects against Gram-negative bacteria but very weak activity against Gram-positive bacteria. Remarkably, ΔPb-CATH4 showed potent activity against antibiotic-resistant clinical isolates and also was observed to possess very low hemolytic activity and cytotoxicity. ΔPb-CATH4 also showed considerable serum stability. Electron microscopic analysis indicated that ΔPb-CATH4 exerts its effects via toroidal pore preformation. Structural comparison of the cathelicidins identified in this study to previously reported ones revealed that these Pb-CATHs are representatives of a new group of reptilian cathelicidins lacking the acidic connecting domain. Furthermore, Pb-CATH4 possesses a completely different mature peptide sequence from those of previously described reptilian cathelicidins. These new AMPs may be candidates for the development of alternatives to or complements of antibiotics to control multidrug-resistant pathogens. Copyright © 2017 American Society for Microbiology.

Genomewide Analysis of the Antimicrobial Peptides in Python bivittatus and Characterization of Cathelicidins with Potent Antimicrobial Activity and Low Cytotoxicity

PubMed Central

Kim, Dayeong; Soundrarajan, Nagasundarapandian; Lee, Juyeon; Cho, Hye-sun; Choi, Minkyeung; Cha, Se-Yeoun; Ahn, Byeongyong; Jeon, Hyoim; Le, Minh Thong; Song, Hyuk; Kim, Jin-Hoi

2017-01-01

ABSTRACT In this study, we sought to identify novel antimicrobial peptides (AMPs) in Python bivittatus through bioinformatic analyses of publicly available genome information and experimental validation. In our analysis of the python genome, we identified 29 AMP-related candidate sequences. Of these, we selected five cathelicidin-like sequences and subjected them to further in silico analyses. The results showed that these sequences likely have antimicrobial activity. The sequences were named Pb-CATH1 to Pb-CATH5 according to their sequence similarity to previously reported snake cathelicidins. We predicted their molecular structure and then chemically synthesized the mature peptide for three putative cathelicidins and subjected them to biological activity tests. Interestingly, all three peptides showed potent antimicrobial effects against Gram-negative bacteria but very weak activity against Gram-positive bacteria. Remarkably, ΔPb-CATH4 showed potent activity against antibiotic-resistant clinical isolates and also was observed to possess very low hemolytic activity and cytotoxicity. ΔPb-CATH4 also showed considerable serum stability. Electron microscopic analysis indicated that ΔPb-CATH4 exerts its effects via toroidal pore preformation. Structural comparison of the cathelicidins identified in this study to previously reported ones revealed that these Pb-CATHs are representatives of a new group of reptilian cathelicidins lacking the acidic connecting domain. Furthermore, Pb-CATH4 possesses a completely different mature peptide sequence from those of previously described reptilian cathelicidins. These new AMPs may be candidates for the development of alternatives to or complements of antibiotics to control multidrug-resistant pathogens. PMID:28630199

Characterization of a Multipeptide Lantibiotic Locus in Streptococcus pneumoniae.

PubMed

Maricic, Natalie; Anderson, Erica S; Opipari, AnneMarie E; Yu, Emily A; Dawid, Suzanne

2016-01-26

Bacterial communities are established through a combination of cooperative and antagonistic interactions between the inhabitants. Competitive interactions often involve the production of antimicrobial substances, including bacteriocins, which are small antimicrobial peptides that target other community members. Despite the nearly ubiquitous presence of bacteriocin-encoding loci, inhibitory activity has been attributed to only a small fraction of gene clusters. In this study, we characterized a novel locus (the pld locus) in the pathogen Streptococcus pneumoniae that drives the production of a bacteriocin called pneumolancidin, which has broad antimicrobial activity. The locus encodes an unusual tandem array of four inhibitory peptides, three of which are absolutely required for antibacterial activity. The three peptide sequences are similar but appear to play distinct roles in regulation and inhibition. A modification enzyme typically found in loci encoding a class of highly modified bacteriocins called lantibiotics was required for inhibitory activity. The production of pneumolancidin is controlled by a two-component regulatory system that is activated by the accumulation of modified peptides. The locus is located on a mobile element that has been found in many pneumococcal lineages, although not all elements carry the pld genes. Intriguingly, a minimal region containing only the genes required for pneumolancidin immunity was found in several Streptococcus mitis strains. The pneumolancidin-producing strain can inhibit nearly all pneumococci tested to date and provided a competitive advantage in vivo. These peptides not only represent a unique strategy for bacterial competition but also are an important resource to guide the development of new antimicrobials. Successful colonization of a polymicrobial host surface is a prerequisite for the subsequent development of disease for many bacterial pathogens. Bacterial factors that directly inhibit the growth of neighbors may provide an advantage during colonization if the inhibition of competitors outweighs the energy for production. In this work, we found that production of a potent antimicrobial called pneumolancidin conferred a competitive advantage to the pathogen Streptococcus pneumoniae. S. pneumoniae secreting pneumolancidin inhibits a wide array of Gram-positive organisms, including all but one tested pneumococcal strain. The pneumolancidin genetic locus is of particular interest because it encodes three similar modified peptides (lantibiotics), each of which has a distinct role in the function of the locus. Lantibiotics represent a relatively untapped resource for the development of clinically useful antibiotics which are desperately needed. The broad inhibitory activity of pneumolancidin makes it an ideal candidate for further characterization and development. Copyright © 2016 Maricic et al.

Synthesis and antimicrobial activity of 1-benzhydryl-sulfonyl-4-(3-(piperidin-4-yl) propyl)piperidine derivatives against pathogens of Lycopersicon esculentum: a structure-activity evaluation study.

PubMed

Vinaya, K; Kavitha, R; Ananda Kumar, C S; Benaka Prasad, S B; Chandrappa, S; Deepak, S A; Nanjunda Swamy, S; Umesha, S; Rangappa, K S

2009-01-01

Several 1-benzhydryl-sulfonyl-4-(3-(piperidin-4-yl)propyl)piperidine derivatives 8(a-j) were prepared by the treatment of substituted benzhydryl chlorides with 4-(3-(piperidin-4-yl)propyl)piperidine followed by N-sulfonation with sulfonyl chlorides in the presence of dry methylene dichloride and triethyl amine. The synthesized compounds were characterized by (1)H-NMR, IR, and elemental analysis. All the synthesized compounds were evaluated in vitro for their efficacy as antimicrobial agents by artificial inoculation technique against standard strains of two important bacterial viz., Xanthomonas axonopodis pv. vesicatoria and Ralstonia solanacearum as well as and two fungal pathogens namely Alternaria solani and Fusarium solani of tomato plants. We have briefly investigated the structure-activity relation studies and reveal that the nature of substitutions on benzhydryl ring and sulfonamide ring influences the antibacterial activity. Among the synthesized new compounds 8b, 8d, 8g, 8h, 8i, and 8j were showed significant potent antimicrobial activities compared to the standard drugs chloramphenicol, mancozeb.

Microencapsulation, Chemical Characterization, and Antimicrobial Activity of Mexican (Lippia graveolens H.B.K.) and European (Origanum vulgare L.) Oregano Essential Oils

PubMed Central

Regalado-González, Carlos; Vázquez-Landaverde, Pedro; Guerrero-Legarreta, Isabel; García-Almendárez, Blanca E.

2014-01-01

The effect of solvent polarity (methanol and pentane) on the chemical composition of hydrodistilled essential oils (EO's) of Lippia graveolens H.B.K. (MXO) and Origanum vulgare L. (EUO) was studied by GC-MS. Composition of modified starch microencapsulated EO's was conducted by headspace-solid-phase microextraction (HS-SPME). The antimicrobial activity of free and microencapsulated EO's was evaluated. They were tested against Salmonella sp., Brochothrix thermosphacta, Pseudomonas fragi, Lactobacillus plantarum, and Micrococcus luteus. Thymol and carvacrol were among the main components of EO's and their free and microencapsulated inhibitory activity was tested against M. luteus, showing an additive combined effect. Chemical composition of EO's varied according to the solvent used for GC analysis and to volatile fraction as evaluated by HS-SPME. Thymol (both solvents) was the main component in essential oil of MXO, while carvacrol was the main component of the volatile fraction. EUO showed α-pinene (methanol) and γ-terpinene (pentane) as major constituents, the latter being the main component of the volatile fraction. EO's showed good stability after 3 months storage at 4°C, where antimicrobial activity of microencapsulated EO's remained the same, while free EO's decreased 41% (MXO) and 67% (EUO) from initial activity. Microencapsulation retains most antimicrobial activity and improves stability of EO's from oregano. PMID:25177730

Microencapsulation, chemical characterization, and antimicrobial activity of Mexican (Lippia graveolens H.B.K.) and European (Origanum vulgare L.) oregano essential oils.

PubMed

Hernández-Hernández, Elvia; Regalado-González, Carlos; Vázquez-Landaverde, Pedro; Guerrero-Legarreta, Isabel; García-Almendárez, Blanca E

2014-01-01

The effect of solvent polarity (methanol and pentane) on the chemical composition of hydrodistilled essential oils (EO's) of Lippia graveolens H.B.K. (MXO) and Origanum vulgare L. (EUO) was studied by GC-MS. Composition of modified starch microencapsulated EO's was conducted by headspace-solid-phase microextraction (HS-SPME). The antimicrobial activity of free and microencapsulated EO's was evaluated. They were tested against Salmonella sp., Brochothrix thermosphacta, Pseudomonas fragi, Lactobacillus plantarum, and Micrococcus luteus. Thymol and carvacrol were among the main components of EO's and their free and microencapsulated inhibitory activity was tested against M. luteus, showing an additive combined effect. Chemical composition of EO's varied according to the solvent used for GC analysis and to volatile fraction as evaluated by HS-SPME. Thymol (both solvents) was the main component in essential oil of MXO, while carvacrol was the main component of the volatile fraction. EUO showed α-pinene (methanol) and γ-terpinene (pentane) as major constituents, the latter being the main component of the volatile fraction. EO's showed good stability after 3 months storage at 4°C, where antimicrobial activity of microencapsulated EO's remained the same, while free EO's decreased 41% (MXO) and 67% (EUO) from initial activity. Microencapsulation retains most antimicrobial activity and improves stability of EO's from oregano.

A Comparison between Characterization and Biological Properties of Brazilian Fresh and Aged Propolis

PubMed Central

Schmidt, Eduardo Morgado; Stock, Daniele; Chada, Fabio José Garcia; Finger, Daiane; Christine Helena Frankland Sawaya, Alexandra; Eberlin, Marcos Nogueira; Felsner, Maria Lurdes; Quináia, Sueli Pércio; Torres, Yohandra Reyes

2014-01-01

Objective. As propolis is a highly valued bee product, we aimed to verify the quality of aged propolis, investigating their phenolic and flavonoid composition, levels of toxic metals, radical scavenging and antimicrobial activities. Material and Methods. Samples of fresh and aged propolis of six different beekeepers, from the same geographical location, were investigated in terms of their phenolic and flavonoid composition and levels of Pb, Cd, and Cr, as well as radical scavenging and antimicrobial activities. Results. The two groups of propolis had similar qualitative composition by HPLC-PDA and ESI(-)-MS. Fresh propolis and aged propolis show no differences when average values of extraction yield, flavonoids, EC50, or MIC were compared and both types of propolis showed good antimicrobial activity at low concentrations. Only levels of phenolic compounds were higher in fresh propolis. Conclusion. The propolis samples considered in this study, aged or fresh, had similar qualitative composition, although they were collected in different periods. Samples only differed in their levels of total phenolic content. Moreover, aged propolis conserves significant radical scavenging and antimicrobial properties. We suggest that aged propolis should not be discarded but explored for alternative applications. PMID:25530958

Isolation and characterization of an anti-leishmanial disintegrin from Cerastes cerastes venom.

PubMed

Allane, Dihia; Oussedik-Oumehdi, Habiba; Harrat, Zoubir; Seve, Michel; Laraba-Djebari, Fatima

2018-02-01

Investigating new antimicrobial and antiparasitic components from Viperidae venoms represents an alternative therapeutic strategy. In this study, we report the characterization of a disintegrin isolated from Cerastes cerastes venom, exhibiting antiparasitic activity on Leishmania infantum promastigotes. Indeed, isolated disintegrin, referred to Disintegrin_Cc, induced 84.75% of parasiticidal activity and deep morphological alterations on the parasites. SDS-PAGE analysis indicated that this disintegrin was homogenous. This dimeric disintegrin of 14,193.97 Da contains an RGD domain and four intramolecular disulfide bridges. It presents a high percentage of identity with other related snake disintegrins. Predicted 3D structure indicated that this peptide shares partial homology with well-known active antimicrobial peptides. Disintegrin_Cc inhibited 80% of arachidonic acid-induced platelet aggregation. The obtained results suggest that the isolated molecule plays a dual role as a disintegrin and as an anti-leishmanial compound. This component could be useful as a drug in the treatment of leishmaniasis. © 2017 Wiley Periodicals, Inc.

Cultivated strains of Agaricus bisporus and A. brasiliensis: chemical characterization and evaluation of antioxidant and antimicrobial properties for the final healthy product--natural preservatives in yoghurt.

PubMed

Stojković, Dejan; Reis, Filipa S; Glamočlija, Jasmina; Ćirić, Ana; Barros, Lillian; Van Griensven, Leo J L D; Ferreira, Isabel C F R; Soković, Marina

2014-07-25

Agaricus bisporus (J. E. Lange) Emil J. Imbach and Agaricus brasiliensis Wasser, M. Didukh, Amazonas & Stamets are edible mushrooms. We chemically characterized these mushrooms for nutritional value, hydrophilic and lipophilic compounds. The antioxidant and antimicrobial activities of methanolic and ethanolic extracts were assessed. Hepatotoxicity was also evaluated. The ethanolic extract of both species was tested for inhibition of Listeria monocytogenes growth in yoghurt. Both species proved to be a good source of bioactive compounds. A. brasiliensis was richer in polyunsaturated fatty acids and revealed the highest concentration of phenolic acids, and tocopherols. A. bisporus showed the highest monounsaturated fatty acids and ergosterol contents. A. brasiliensis revealed the highest antioxidant potential, and its ethanolic extract displayed the highest antibacterial potential; the methanolic extract of A. bisporus revealed the highest antifungal activity. A. brasiliensis possessed better preserving properties in yoghurt.

Characterization of phytoconstituents and evaluation of antimicrobial activity of silver-extract nanoparticles synthesized from Momordica charantia fruit extract.

PubMed

Rashid, Md Mamun Or; Akhter, Kazi Nahid; Chowdhury, Jakir Ahmed; Hossen, Foysal; Hussain, Md Saddam; Hossain, Md Tanvir

2017-06-26

Our present study was conducted to characterize the phytoconstituents present in the aqueous extract of Momordica charantia and evaluate the antimicrobial efficacy of silver-extract nanoparticles (Ag-Extract-NPs). Silver nanoparticles (AgNPs) were prepared by reducing AgNO 3; and NaBH 4 served as reducing agent. After screening of phytochemicals; AgNPs and aqueous extract were mixed thoroughly and then coated by polyaniline. These NPs were characterized by using Visual inspection, UV spectroscopy, FTIR, SEM and TEM techniques. Antimicrobial activities were assessed against Staphylococcus aureus, Salmonella typhi, Escherichia coli and Pseudomonas aeruginosa. Aqueous extract of M. charantia fruits contain alkaloid, phenol, saponin etc. UV-Vis spectrum showed strong absorption peak around 408 nm. The presence of -CH, -NH, -COOH etc. stretching in FTIR spectrum of Ag-Extract-NPs endorsed that AgNPs were successfully capped by bio-compounds. SEM and TEM result revealed that synthesized NPs had particle size 78.5-220 nm. Ag-Extract-NPs showed 34.6 ± 0.8 mm zone of inhibition against E. coli compared to 25.6 ± 0.5 mm for ciprofloxacin. Maximum zone of inhibition for Ag-Extract-NPs were 24.8 ± 0.7 mm, 26.4 ± 0.4 mm, 7.4 ± 0.4 mm for S. aureus, P. aeruginosa and S. typhi. We found that Ag-Extract-NPs have much better antibacterial efficacy than AgNPs and M. charantia extract has individually. It is also noticed that gram negative bacteria (except S. typhi) are more susceptible to Ag-Extract-NPs than gram positive bacteria. Ag-Extract-NPs showed strong antibacterial activity. In order to make a reliable stand for mankind, further study is needed to consider determining the actual biochemical pathway by which AgNPs-extracts exert their antimicrobial effect.

Antibacterial activity and composition of essential oils from Pelargonium graveolens L'Her and Vitex agnus-castus L.

PubMed

Ghannadi, A; Bagherinejad, Mr; Abedi, D; Jalali, M; Absalan, B; Sadeghi, N

2012-12-01

Essential oils are volatile compounds that have been used since Middle Ages as antimicrobial, anti-inflammatory, sedative, local anesthetic and food flavoring agents. In the current study, essential oils of Pelargonium graveolens L'Her and Vitex agnus-castus L. were analyzed for their antibacterial activities. The chemical compositions of essential oils were characterized by GC-MS. Disc diffusion method was used to study antimicrobial activity. Inhibition zones showed that the essential oils of the two plants were active against all of the studied bacteria (except Listeria monocytogenes). The susceptibility of the strains changed with the dilution of essential oils in DMSO. The pure essential oils showed the most extensive inhibition zones and they were very effective antimicrobial compounds compared to chloramphenicol and amoxicillin. The most susceptible strain against these two essential oils was Staphylococcus aureus. It seems that β-citronellol is a prominent part of P. graveolens volatile oil and caryophyllene oxide is a famous and important part of V. agnus-castus volatile oil and their probable synergistic effect with other constituents are responsible for the antibacterial effects of these oils. However further studies must be performed to confirm the safety of these oils for use as antimicrobial agents and natural preservatives in different products.

Isolation, characterization and mode of antimicrobial action against Vibrio cholerae of methyl gallate isolated from Acacia farnesiana.

PubMed

Sánchez, E; Heredia, N; Camacho-Corona, M Del R; García, S

2013-12-01

The antimicrobial activity of Acacia farnesiana against Vibrio cholerae has been demonstrated; however, no information regarding its active compound or its mechanism of action has been documented. The active compound was isolated from A. farnesiana by bioassay-guided fractionation and identified as methyl gallate by nuclear magnetic resonance (NMR) techniques ((1) H NMR and (13) C NMR). The minimum bactericidal concentration (MBC) of methyl gallate and its effect on membrane integrity, cytoplasmic pH, membrane potential, ATP synthesis and gene expression of cholera toxin (ctx) from V. cholerae were determined. The MBC of methyl gallate ranged from 30 ± 1 to 50 ± 1 μg ml(-1) . Methyl gallate affected cell membrane integrity, causing a decrease in cytoplasmic pH (pHin , from 7·3 to <3·0), and membrane hyperpolarization, and ATP was no longer produced by the treated cells. However, methyl gallate did not affect ctx gene expression. Methyl gallate is a major antimicrobial compound from A. farnesiana that disturbs the membrane activity of V. cholerae. The effects of methyl gallate validate several traditional antimicrobial uses of A. farnesiana, and it is an attractive alternative to control V. cholerae. © 2013 The Society for Applied Microbiology.

Antitumor and antimicrobial activities of endophytic fungi from medicinal parts of Aquilaria sinensis.

PubMed

Cui, Jin-long; Guo, Shun-xing; Xiao, Pei-gen

2011-05-01

The purpose of this study was to isolate and characterize endophytic fungi from the stem tissue which can produce fragrant ingredients in Aquilaria sinensis (also called agarwood) to determine their antitumor and antimicrobial activities. Twenty-eight fungal endophytes were isolated from agarwood by strict sterile sample preparation and were classified into 14 genera and 4 taxonomic classes (Sordariomycetes, Dothideomycetes, Saccharomycetes, and Zygomycetes) based on molecular identification. Of the 28 isolates, 13 (46.4%) showed antimicrobial activity against at least one of the test strains by the agar well diffusion method, and 23 isolates (82.1%) displayed antitumor activity against at least one of five cancer cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The diameters of inhibition zones of YNAS07, YNAS14, HNAS04, HNAS05, HNAS08, and HNAS11 were equal to or higher than 14.0 mm against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, B. subtilis, Aspergillus fumigatus, and B. subtilis, respectively. The inhibition rates of YNAS06, YNAS08, and HNAS06 were not less than 60% to 293-T, 293-T, and SKVO3 cells, respectively. These results suggest that the endophytic fungi associated with agarwood will provide us with not only useful micro-ecological information, but also potential antimicrobial and antitumor agents.

Size-dependent antimicrobial properties of the cobalt ferrite nanoparticles

NASA Astrophysics Data System (ADS)

Žalnėravičius, Rokas; Paškevičius, Algimantas; Kurtinaitiene, Marija; Jagminas, Arūnas

2016-10-01

The growing resistance of bacteria to conventional antibiotics elicited considerable interest to non-typical drugs. In this study, antimicrobial investigations were performed on low-size dispersion cobalt ferrite nanoparticles (Nps) fabricated by co-precipitation approach in several average sizes, in particular, 15.0, 5.0, and 1.65 nm. A variety of experimental tests demonstrated that the size of these Nps is determinant for antimicrobial efficiency against S. cerevisiae and several Candida species, in particular, C. parapsilosis, C. krusei, and C. albicans. The small and ultra-small fractions of CoFe2O4 Nps possess especially strong antimicrobial activity against all tested microorganisms. The possible reasons are discussed. Nps were characterized by means of transmission and high-resolution transmission electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy and atomic force microscopy, chemical analysis and magnetic measurements.

Purification and characterization of antimicrobial peptides from the Caribbean frog, Leptodactylus validus (Anura: Leptodactylidae).

PubMed

King, Jay D; Leprince, Jérôme; Vaudry, Hubert; Coquet, Laurent; Jouenne, Thierry; Conlon, J Michael

2008-08-01

Peptidomic analysis of norepinephrine-stimulated skin secretions from the Caribbean frog Leptodactylus validus Garman, 1888 led to the identification of three peptides with previously undescribed sequences that were structurally similar to those of antimicrobial peptides isolated from other species of leptodactylid frogs. These paralogs have been termed ocellatin-V1 (GVVDILKGAGKDLLAHALSKLSEKV.NH(2)), ocellatin-V2 (GVLDILKGAGKDLLAHALSKISEKV.NH(2)), and ocellatin-V3 (GVLDILTGAGKDLLAHALSKLSEKV.NH(2)). The very low antimicrobial potency (MIC>200microM) against Escherichia coli and Staphylococcus aureus associated with the peptides is probably a consequence of their lack of amphipathicity and reduced cationicity compared with active members of the ocellatin family from related species.

Characterization and antimicrobial performance of nano silver coatings on leather materials

PubMed Central

Lkhagvajav, N.; Koizhaiganova, M.; Yasa, I.; Çelik, E.; Sari, Ö.

2015-01-01

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/cm 2 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/cm 2 of nAg demonstrated the highest antibacterial activity against E. coli with 99.25% bacterium removal, whereas a 10 μg/cm 2 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. PMID:26221087

1-Formyl-3-phenyl-5-(4-isopropylphenyl)-2-pyrazoline: Synthesis, characterization, antimicrobial activity and DFT studies

NASA Astrophysics Data System (ADS)

Sid, Assia; Messai, Amel; Parlak, Cemal; Kazancı, Nadide; Luneau, Dominique; Keşan, Gürkan; Rhyman, Lydia; Alswaidan, Ibrahim A.; Ramasami, Ponnadurai

2016-10-01

The structure of 1-formyl-3-phenyl-5-(4-isopropylphenyl)-2-pyrazoline synthesized as single crystal was investigated by FTIR, NMR, XRD. Experimental data were complemented by quantum mechanical calculations. XRD data show that the compound crystallizes in the triclinic system (P-1) via trans isomer (a = 6.4267(4) Å, b = 10.9259(12) Å, c = 12.4628(9) Å and α = 102.894(8)°, β = 102.535(6)°, γ = 101.633(7)°). Anti-microbial screening results indicate that the compound shows promising activity. The theoretically predicted and experimentally obtained parameters reveal further insight into pyrazoline systems.

Genomic and functional characterization of three new venom peptides from the scorpion Heterometrus spinifer.

PubMed

Wu, Shifen; Nie, Yao; Zeng, Xian-Chun; Cao, Hanjun; Zhang, Lei; Zhou, Lingli; Yang, Ye; Luo, Xuesong; Liu, Yichen

2014-03-01

Three new cysteine-free venom peptides, which are referred to as Heterin-1, Heterin-2 and Spiniferin, respectively, were identified from the scorpion Heterometrus spinifer. Heterin-1, Heterin-2 and Spiniferin contain 43, 24 and 13 amino acid residues, respectively. Genomic analysis showed that the genomic organizations of the three peptides are consistent with those of the known Na(+), K(+) or Cl(-)-channel specific toxins from scorpions; this suggests that the genes of the cysteine-free and cysteine-rich peptides from scorpions were derived from a common ancestor. Antimicrobial assay demonstrated that Heterin-1 possesses potent activities against both Gram-positive and Gram-negative bacteria. Among the tested bacterial species, Heterin-1 is the most active against Bacillus megaterium and Micrococcus luteus with MICs of 4.0 μM and 4.0 μM, respectively. Heterin-2 is able to potently inhibit the growth of Gram-positive bacteria with MICs from 5.6 μM to 30.0 μM; however, it has weaker activities against the tested Gram-negative bacteria. It is interesting to see that deletion of the C-terminal random coiled tail (KKD) in Heterin-2 markedly changed the antimicrobial specificity and activity of the peptide. Spiniferin has very weak antimicrobial activities against both Gram-positive and Gram-negative bacteria. We found that introducing three net charges into the polar face of Spiniferin significantly increased its antimicrobial activity against the majority of the tested bacteria; however, in some instances, net charge on the polar face is not important for the antimicrobial activity of the peptide. These studies have expanded our understanding of the diversity, evolution and structure/function relationships of the cysteine-free peptides from scorpions. Copyright © 2013 Elsevier Inc. All rights reserved.

Green synthesis and characterization of zinc oxide nanoparticle using insulin plant (Costus pictus D. Don) and investigation of its antimicrobial as well as anticancer activities

NASA Astrophysics Data System (ADS)

Suresh, Joghee; Pradheesh, Ganeshan; Alexramani, Vincent; Sundrarajan, Mahalingam; Hong, Sun Ig

2018-03-01

In this work we aim to synthesize biocompatible ZnO nanoparticles from the zinc nitrate via green process using leaf extracts of the Costus pictus D. Don medicinal plant. FTIR studies confirm the presence of biomolecules and metal oxides. X-ray diffraction (XRD) structural analysis reveals the formation of pure hexagonal phase structures of ZnO nanoparticles. The surface morphologies of ZnO nanoparticles observed under a scanning electron microscope (SEM) suggest that most ZnO crystallites are hexagonal. EDX analysis confirms the presence of primarily zinc and oxygen. TEM images show that biosynthesized zinc oxide nanoparticles are hexagonal and spherical. The plausible formation mechanisms of zinc oxide nanoparticles are also predicted. The biosynthesized zinc oxide nanoparticles exhibit strong antimicrobial behavior against bacterial and fungal species when employing the agar diffusion method. Synthesized ZnO nanoparticles exhibit anticancer activity against Daltons lymphoma ascites (DLA) cells as well as antimicrobial activity against some bacterial and fungal strains.

Preparation and characterization of essential oil-loaded starch nanoparticles formed by short glucan chains.

PubMed

Qiu, Chao; Chang, Ranran; Yang, Jie; Ge, Shengju; Xiong, Liu; Zhao, Mei; Li, Man; Sun, Qingjie

2017-04-15

Essential oils (EOs), including menthone, oregano, cinnamon, lavender, and citral, are natural products that have antimicrobial and antioxidant activities. However, extremely low water solubility, and easy degradation by heat, restrict their application. The aim of this work was to evaluate the enhancement in antioxidative and antimicrobial activities of EOs encapsulated in starch nanoparticles (SNPs) prepared by short glucan chains. For the first time, we have successfully fabricated menthone-loaded SNPs (SNPs-M) at different complexation temperatures (30, 60, and 90°C) by an in situ nanoprecipitation method. The SNPs-M displayed spherical shapes, and the particle sizes ranged from 93 to 113nm. The encapsulation efficiency (EE) of SNPs-M increased significantly with an increase in complexation temperature, and the maximum EE was 86.6%. The SNPs-M formed at 90°C had high crystallization and thermal stability. The durations of the antioxidant and antimicrobial activities of EOs was extended by their encapsulation in the SNPs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis, characteristics and antimicrobial activity of ZnO nanoparticles

NASA Astrophysics Data System (ADS)

Janaki, A. Chinnammal; Sailatha, E.; Gunasekaran, S.

2015-06-01

The utilization of various plant resources for the bio synthesis of metallic nano particles is called green technology and it does not utilize any harmful protocols. Present study focuses on the green synthesis of ZnO nano particles by Zinc Carbonate and utilizing the bio-components of powder extract of dry ginger rhizome (Zingiber officinale). The ZnO nano crystallites of average size range of 23-26 nm have been synthesized by rapid, simple and eco friendly method. Zinc oxide nano particles were characterized by using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray spectroscopy (EDX). FTIR spectra confirmed the adsorption of surfactant molecules at the surface of ZnO nanoparticles and the presence of ZnO bonding. Antimicrobial activity of ZnO nano particles was done by well diffusion method against pathogenic organisms like Klebsiella pneumonia, Staphylococcus aureus and Candida albicans and Penicillium notatum. It is observed that the ZnO synthesized in the process has the efficient antimicrobial activity.

Characterization of anticancer, antimicrobial, antioxidant properties and chemical compositions of Peperomia pellucida leaf extract.

PubMed

Wei, Lee Seong; Wee, Wendy; Siong, Julius Yong Fu; Syamsumir, Desy Fitrya

2011-01-01

Peperomia pellucida leaf extract was characterized for its anticancer, antimicrobial, antioxidant activities, and chemical compositions. Anticancer activity of P. pellucida leaf extract was determined through Colorimetric MTT (tetrazolium) assay against human breast adenocarcinoma (MCF-7) cell line and the antimicrobial property of the plant extract was revealed by using two-fold broth micro-dilution method against 10 bacterial isolates. Antioxidant activity of the plant extract was then characterized using α, α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging method and the chemical compositions were screened and identified using gas chromatography-mass spectrometry (GC-MS). The results of present study indicated that P. pellucida leaf extract possessed anticancer activities with half maximal inhibitory concentration (IC(50)) of 10.4 ± 0.06 µg/ml. The minimum inhibitory concentration (MIC) values were ranged from 31.25 to 125 mg/l in which the plant extract was found to inhibit the growth of Edwardsiella tarda, Escherichia coli, Flavobacterium sp., Pseudomonas aeruginosa and Vibrio cholerae at 31.25 mg/l; Klebsiella sp., Aeromonas hydrophila and Vibrio alginolyticus at 62.5 mg/l; and it was able to control the growth of Salmonella sp. and Vibrio parahaemolyticus at 125 mg/l. At the concentration of 0.625 ppt, the plant extract was found to inhibit 30% of DPPH, free radical. Phytol (37.88%) was the major compound in the plant extract followed by 2-Naphthalenol, decahydro- (26.20%), Hexadecanoic acid, methyl ester (18.31%) and 9,12-Octadecadienoic acid (Z,Z)-, methyl ester (17.61%). Findings from this study indicated that methanol extract of P. pellucida leaf possessed vast potential as medicinal drug especially in breast cancer treatment.

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

PubMed

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

2017-06-01

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

Characterization of an Olive Flounder Bone Gelatin-Zinc Oxide Nanocomposite Film and Evaluation of Its Potential Application in Spinach Packaging.

PubMed

Beak, Songee; Kim, Hyeri; Song, Kyung Bin

2017-11-01

Olive flounder bone gelatin (OBG) was used for a film base material in this study. In addition, zinc oxide nanoparticles (ZnO) were incorporated into the OBG film to prepare a nanocomposite film and to impart antimicrobial activity to it. The tensile strength of the OBG film increased by 6.62 MPa, and water vapor permeability and water solubility decreased by 0.93 × 10 -9 g/m s Pa and 13.79%, respectively, by the addition of ZnO to the OBG film. In particular, the OBG-ZnO film exhibited antimicrobial activity against Listeria monocytogenes. To investigate the applicability of the OBG-ZnO packaging film, fresh spinach was wrapped in this film and stored for a week. The results indicated that the OBG-ZnO film showed antimicrobial activity against L. monocytogenes inoculated on spinach without affecting the quality of spinach, such as vitamin C content and color. Thus, the OBG-ZnO nanocomposite film can be applied as an efficient antimicrobial food packaging material. As a base material of edible films, gelatin was extracted from olive flounder bone, which is fish processing by-product. Olive flounder bone gelatin (OBG) nanocomposite films were prepared with zinc oxide nanoparticles (ZnO). For an application to antimicrobial packaging, spinach was wrapped with the OBG-ZnO nanocomposite film. © 2017 Institute of Food Technologists®.

Synthesis, crystal structures, spectral, thermal and antimicrobial properties of new Zn(II) 5-iodo- and 5-bromosalicylates

NASA Astrophysics Data System (ADS)

Košická, Petra; Győryová, Katarína; Smolko, Lukáš; Gyepes, Róbert; Hudecová, Daniela

2018-03-01

Two new analogous zinc(II) complexes containing 5-iodo- and 5-bromosalicylate ligands, respectively, were prepared in single-crystal form and characterized by IR spectroscopy, thermal analysis and elemental analysis. The solid-state structures of prepared complexes were determined by single crystal X-ray crystallography. Both complexes are isostructural and their crystal structures composed of neutral molecules [Zn(5-Xsal)2(H2O)2] (where X = Br, I, sal = salicylato). Central Zn(II) atom is in both complexes coordinated by six oxygen atoms, four of which are from two chelate bonded 5-halosalicylates and remaining two from coordinated water molecules. The found chelate binding mode is in line with the Δ values calculated from IR spectral data. Antimicrobial activity of prepared complexes was studied against selected bacteria, yeast and filamentous fungi. Obtained results indicate that 5-iodosalicylate complex is more antimicrobially active than its 5-bromo substituted analogue.

Enhanced antimicrobial activities of silver-nanoparticle-decorated reduced graphene nanocomposites against oral pathogens.

PubMed

Peng, Jian-Min; Lin, Jia-Cheng; Chen, Zhuo-Yu; Wei, Meng-Chao; Fu, Yuan-Xiang; Lu, Shu-Shen; Yu, Dong-Sheng; Zhao, Wei

2017-02-01

As a means of capitalizing on the synergistic properties between reduced graphene nanosheets (R-GNs) and silver nanoparticles (AgNPs), an efficient and convenient chemical reduction method was used to prepare silver-nanoparticle-decorated reduced graphene nanocomposites (R-GNs/Ag). The products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy, which confirmed the loading of well-dispersed silver nanoparticles on reduced graphene sheets. Their antimicrobial activities against oral pathogens such as Candida albicans, Lactobacillus acidophilus, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans were investigated by MIC determination, the counting of colony-forming units (CFU), agar diffusion tests, and growth curve observation. Compared with pure R-GNs and AgNPs, R-GNs/Ag composites exhibited enhanced antimicrobial properties owing to highly dispersed AgNPs on R-GNs. Copyright © 2016 Elsevier B.V. All rights reserved.

Semisynthetic Phenol Derivatives Obtained from Natural Phenols: Antimicrobial Activity and Molecular Properties.

PubMed

Pinheiro, Patrícia Fontes; Menini, Luciana Alves Parreira; Bernardes, Patrícia Campos; Saraiva, Sérgio Henriques; Carneiro, José Walkimar Mesquita; Costa, Adilson Vidal; Arruda, Társila Rodrigues; Lage, Mateus Ribeiro; Gonçalves, Patrícia Martins; Bernardes, Carolina de Oliveira; Alvarenga, Elson Santiago; Menini, Luciano

2018-01-10

Semisynthetic phenol derivatives were obtained from the natural phenols: thymol, carvacrol, eugenol, and guaiacol through catalytic oxychlorination, Williamson synthesis, and aromatic Claisen rearrangement. The compounds characterization was carried out by 1 H NMR, 13 C NMR, and mass spectrometry. The natural phenols and their semisynthetic derivatives were tested for their antimicrobial activity against the bacteria: Staphylococcus aureus, Escherichia coli, Listeria innocua, Pseudomonas aeruginosa, Salmonella enterica Typhimurium, Salmonella enterica ssp. enterica, and Bacillus cereus. Minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values were determined using concentrations from 220 to 3.44 μg mL -1 . Most of the tested compounds presented MIC values ≤220 μg mL -1 for all the bacteria used in the assays. The molecular properties of the compounds were computed with the PM6 method. Through principle components analysis, the natural phenols and their semisynthetic derivatives with higher antimicrobial potential were grouped.

Characterization of Histone H2A Derived Antimicrobial Peptides, Harriottins, from Sicklefin Chimaera Neoharriotta pinnata (Schnakenbeck, 1931) and Its Evolutionary Divergence with respect to CO1 and Histone H2A.

PubMed

Sathyan, Naveen; Philip, Rosamma; Chaithanya, E R; Anil Kumar, P R; Sanjeevan, V N; Singh, I S Bright

2013-01-01

Antimicrobial peptides (AMPs) are humoral innate immune components of fishes that provide protection against pathogenic infections. Histone derived antimicrobial peptides are reported to actively participate in the immune defenses of fishes. Present study deals with identification of putative antimicrobial sequences from the histone H2A of sicklefin chimaera, Neoharriotta pinnata. A 52 amino acid residue termed Harriottin-1, a 40 amino acid Harriottin-2, and a 21 mer Harriottin-3 were identified to possess antimicrobial sequence motif. Physicochemical properties and molecular structure of Harriottins are in agreement with the characteristic features of antimicrobial peptides, indicating its potential role in innate immunity of sicklefin chimaera. The histone H2A sequence of sicklefin chimera was found to differ from previously reported histone H2A sequences. Phylogenetic analysis based on histone H2A and cytochrome oxidase subunit-1 (CO1) gene revealed N. pinnata to occupy an intermediate position with respect to invertebrates and vertebrates.

Characterization of Histone H2A Derived Antimicrobial Peptides, Harriottins, from Sicklefin Chimaera Neoharriotta pinnata (Schnakenbeck, 1931) and Its Evolutionary Divergence with respect to CO1 and Histone H2A

PubMed Central

Sathyan, Naveen; Philip, Rosamma; Chaithanya, E. R.; Anil Kumar, P. R.; Sanjeevan, V. N.; Singh, I. S. Bright

2013-01-01

Antimicrobial peptides (AMPs) are humoral innate immune components of fishes that provide protection against pathogenic infections. Histone derived antimicrobial peptides are reported to actively participate in the immune defenses of fishes. Present study deals with identification of putative antimicrobial sequences from the histone H2A of sicklefin chimaera, Neoharriotta pinnata. A 52 amino acid residue termed Harriottin-1, a 40 amino acid Harriottin-2, and a 21 mer Harriottin-3 were identified to possess antimicrobial sequence motif. Physicochemical properties and molecular structure of Harriottins are in agreement with the characteristic features of antimicrobial peptides, indicating its potential role in innate immunity of sicklefin chimaera. The histone H2A sequence of sicklefin chimera was found to differ from previously reported histone H2A sequences. Phylogenetic analysis based on histone H2A and cytochrome oxidase subunit-1 (CO1) gene revealed N. pinnata to occupy an intermediate position with respect to invertebrates and vertebrates. PMID:27398241

Structural and biophysical characterization of an antimicrobial peptide chimera comprised of lactoferricin and lactoferrampin.

PubMed

Haney, Evan F; Nazmi, Kamran; Bolscher, Jan G M; Vogel, Hans J

2012-03-01

Lactoferricin and lactoferrampin are two antimicrobial peptides found in the N-terminal lobe of bovine lactoferrin with broad spectrum antimicrobial activity against a range of Gram-positive and Gram-negative bacteria as well as Candida albicans. A heterodimer comprised of lactoferrampin joined to a fragment of lactoferricin was recently reported in which these two peptides were joined at their C-termini through the two amino groups of a single Lys residue (Bolscher et al., 2009, Biochimie 91(1):123-132). This hybrid peptide, termed LFchimera, has significantly higher antimicrobial activity compared to the individual peptides or an equimolar mixture of the two. In this work, the underlying mechanism behind the increased antibacterial activity of LFchimera was investigated. Differential scanning calorimetry studies demonstrated that all the peptides influenced the thermotropic phase behaviour of anionic phospholipid suspensions. Calcein leakage and vesicle fusion experiments with anionic liposomes revealed that LFchimera had enhanced membrane perturbing properties compared to the individual peptides. Peptide structures were evaluated using circular dichroism and NMR spectroscopy to gain insight into the structural features of LFchimera that contribute to the increased antimicrobial activity. The NMR solution structure, determined in a miscible co-solvent mixture of chloroform, methanol and water, revealed that the Lys linkage increased the helical content in LFchimera compared to the individual peptides, but it did not fix the relative orientations of lactoferricin and lactoferrampin with respect to each other. The structure of LFchimera provides insight into the conformation of this peptide in a membranous environment and improves our understanding of its antimicrobial mechanism of action. Copyright © 2011 Elsevier B.V. All rights reserved.

Chitosan Ascorbate Nanoparticles for the Vaginal Delivery of Antibiotic Drugs in Atrophic Vaginitis

PubMed Central

Vigani, Barbara; Puccio, Antonella; Ferrari, Franca

2017-01-01

The aim of the present work was the development of chitosan ascorbate nanoparticles (CSA NPs) loaded into a fast-dissolving matrix for the delivery of antibiotic drugs in the treatment of atrophic vaginitis. CSA NPs loaded with amoxicillin trihydrate (AX) were obtained by ionotropic gelation in the presence of pentasodium tripolyphosphate (TPP). Different CSA:TPP and CSA:AX weight ratios were considered and their influence on the particle size, polydispersion index and production yield were investigated. CSA NPs were characterized for mucoadhesive, wound healing and antimicrobial properties. Subsequently, CSA NPs were loaded in polymeric matrices, whose composition was optimized using a DoE (Design of Experiments) approach (simplex centroid design). Matrices were obtained by freeze-drying aqueous solutions of three hydrophilic excipients, polyvinylpirrolidone, mannitol and glycin. They should possess a mechanical resistance suitable for the administration into the vaginal cavity and should readily dissolve in the vaginal fluid. In addition to antioxidant properties, due to the presence of ascorbic acid, CSA NPs showed in vitro mucoadhesive, wound healing and antimicrobial properties. In particular, nanoparticles were characterized by an improved antimicrobial activity with respect to a chitosan solution, prepared at the same concentration. The optimized matrix was characterized by mechanical resistance and by the fast release in simulated vaginal fluid of nanoparticles characterized by unchanged size. PMID:29048359

Antimicrobial cellulosic hydrogel from olive oil industrial residue.

PubMed

Dacrory, Sawsan; Abou-Yousef, Hussein; Abouzeid, Ragab E; Kamel, Samir; Abdel-Aziz, Mohamed S; El-Badry, Mohamed

2018-05-25

The cellulose-based antimicrobial hydrogel was prepared from seed and husk cellulosic fibers of olive industry residues by load silver nanoparticles (AgNPs) onto grafted acrylamide monomer (Am) cellulosic fibers. The grafting approach was the free radical mechanism by utilizing ceric ammonium nitrate (CAN) as initiator in aqueous medium and N,N methylene bisacrylamide (MBAm) as a cross linker. The effect of different grafting conditions on the properties of produced hydrogels has been studied by determining the grafting parameters, i.e. concentration of Am, MBAm, grafting time and temperature to optimize grafting yield (G %), grafting efficiency (GE %), and swelling %. Characterizations of the obtained hydrogels were performed through monitoring swelling behavior, FTIR spectroscopy, SEM, and EDX. AgNPs were grown into the prepared hydrogel. Hydrogel/AgNPs were characterized by FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The hydrogel loaded AgNPs exhibit high efficient antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. Copyright © 2018. Published by Elsevier B.V.

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

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

Bactericidal Activity of Usnic Acid-Loaded Electrospun Fibers.

PubMed

Araújo, Evando S; Pereira, Eugênia C; da Costa, Mateus M; da Silva, Nicácio H; de Oliveira, Helinando P

2016-01-01

Usnic acid has been progressively reported in the literature as one of the most important lichen metabolites characterized by a rich diversity of applications such as antifungal, antimicrobial, antiprotozoal and antiviral agent. Particularly, antimicrobial activity of usnic acid can be improved by encapsulation of active molecules in enteric electrospun fibers, allowing the controlled release of active molecule at specific pH. Few relevant patents to the topic have been reviewed and cited. Bactericidal activity of usnic acid-loaded electrospun fibers of Eudragit L-100 and polyvinylpyrrolidone was examined against Staphylococcus aureus using inhibition hales methodology. The controlled release of active material at high pH is established after 10 minutes of interaction with media and results in reasonable activity against S. aureus, as detected by inhibition hales. The strong biological activity of usnic acid-loaded electrospun fibers provides a promising application for corresponding material as a bactericidal agent for wound healing treatment.

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

NASA Astrophysics Data System (ADS)

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 models.

Insights into Comparative Antimicrobial Efficacies of Synthetic and Organic Agents: The Case of ZnS Nanoparticles and Zingiber officinale Rosc.

NASA Astrophysics Data System (ADS)

Obidi, O. F.; Nejo, A. O.; Ayeni, R. A.; Revaprasadu, N.

2018-03-01

The differences among the antimicrobial activities of synthetic nanoparticles (NPs), organic agents and conventional antibiotics against human pathogens are little known. We compared the antimicrobial activities of aqueous, ethanol and ethyl acetate extracts of Zingiber officinale rhizomes with ZnS NPs and tetracycline/nystatin using agar-diffusion techniques. Transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and ultraviolet spectroscopy were used to characterize ZnS NPs. At 100 mg/ml, ethanol and ethyl acetate extract inhibited Acinetobacter baumannii, Salmonella typhimurium, Enterococcus faecium, Shigella flexneri, Klebsiella pneumoniae, Staphylococcus epidermidis and Candida albicans with zones of inhibition (ZOI) ranging between 0-42 mm and 0-39 mm, respectively. Candida albicans had a remarkable ZOI of 42 mm and 22 mm from ethanol and ZnS NPs compared with 20 mm from conventional nystatin. TEM and FTIR revealed spherically shaped polydispersed NPs with particle size of 12.5 nm and the role of banana peel extracts in ZnS NPs synthesis. Organic and synthetic NPs proved potential alternatives to conventional antimicrobial agents.

Insights into Comparative Antimicrobial Efficacies of Synthetic and Organic Agents: The Case of ZnS Nanoparticles and Zingiber officinale Rosc.

NASA Astrophysics Data System (ADS)

Obidi, O. F.; Nejo, A. O.; Ayeni, R. A.; Revaprasadu, N.

2018-06-01

The differences among the antimicrobial activities of synthetic nanoparticles (NPs), organic agents and conventional antibiotics against human pathogens are little known. We compared the antimicrobial activities of aqueous, ethanol and ethyl acetate extracts of Zingiber officinale rhizomes with ZnS NPs and tetracycline/nystatin using agar-diffusion techniques. Transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and ultraviolet spectroscopy were used to characterize ZnS NPs. At 100 mg/ml, ethanol and ethyl acetate extract inhibited Acinetobacter baumannii, Salmonella typhimurium, Enterococcus faecium, Shigella flexneri, Klebsiella pneumoniae, Staphylococcus epidermidis and Candida albicans with zones of inhibition (ZOI) ranging between 0-42 mm and 0-39 mm, respectively. Candida albicans had a remarkable ZOI of 42 mm and 22 mm from ethanol and ZnS NPs compared with 20 mm from conventional nystatin. TEM and FTIR revealed spherically shaped polydispersed NPs with particle size of 12.5 nm and the role of banana peel extracts in ZnS NPs synthesis. Organic and synthetic NPs proved potential alternatives to conventional antimicrobial agents.

Toxicology of antimicrobial nanoparticles for prosthetic devices

PubMed Central

Nuñez-Anita, Rosa Elvira; Acosta-Torres, Laura Susana; Vilar-Pineda, Jorge; Martínez-Espinosa, Juan Carlos; de la Fuente-Hernández, Javier; Castaño, Víctor Manuel

2014-01-01

Advances in nanotechnology are producing an accelerated proliferation of new nanomaterial composites that are likely to become an important source of engineered health-related products. Nanoparticles with antifungal effects are of great interest in the formulation of microbicidal materials. Fungi are found as innocuous commensals and colonize various habitats in and on humans, especially the skin and mucosa. As growth on surfaces is a natural part of the Candida spp. lifestyle, one can expect that Candida organisms colonize prosthetic devices, such as dentures. Macromolecular systems, due to their properties, allow efficient use of these materials in various fields, including the creation of reinforced nanoparticle polymers with antimicrobial activity. This review briefly summarizes the results of studies conducted during the past decade and especially in the last few years focused on the toxicity of different antimicrobial polymers and factors influencing their activities, as well as the main applications of antimicrobial polymers in dentistry. The present study addresses aspects that are often overlooked in nanotoxicology studies, such as careful time-dependent characterization of agglomeration and ion release. PMID:25187703

Inhibition of multidrug resistant Listeria monocytogenes by peptides isolated from combinatorial phage display libraries.

PubMed

Flachbartova, Z; Pulzova, L; Bencurova, E; Potocnakova, L; Comor, L; Bednarikova, Z; Bhide, M

2016-01-01

The aim of the study was to isolate and characterize novel antimicrobial peptides from peptide phage library with antimicrobial activity against multidrug resistant Listeria monocytogenes. Combinatorial phage-display library was used to affinity select peptides binding to the cell surface of multidrug resistant L. monocytogenes. After several rounds of affinity selection followed by sequencing, three peptides were revealed as the most promising candidates. Peptide L2 exhibited features common to antimicrobial peptides (AMPs), and was rich in Asp, His and Lys residues. Peptide L3 (NSWIQAPDTKSI), like peptide L2, inhibited bacterial growth in vitro, without any hemolytic or cytotoxic effects on eukaryotic cells. L1 peptide showed no inhibitory effect on Listeria. Structurally, peptides L2 and L3 formed random coils composed of α-helix and β-sheet units. Peptides L2 and L3 exhibited antimicrobial activity against multidrug resistant isolates of L. monocytogenes with no haemolytic or toxic effects. Both peptides identified in this study have the potential to be beneficial in human and veterinary medicine. Copyright © 2016 Elsevier GmbH. All rights reserved.

Synthesized zinc peroxide nanoparticles (ZnO2-NPs): a novel antimicrobial, anti-elastase, anti-keratinase, and anti-inflammatory approach toward polymicrobial burn wounds.

PubMed

Ali, Sameh Samir; Morsy, Reda; El-Zawawy, Nessma Ahmed; Fareed, Mervat F; Bedaiwy, Mohamed Yaser

2017-01-01

Increasing of multidrug resistance (MDR) remains an intractable challenge for burn patients. Innovative nanomaterials are also in high demand for the development of new antimicrobial biomaterials that inevitably have opened new therapeutic horizons in medical approaches and lead to many efforts for synthesizing new metal oxide nanoparticles (NPs) for better control of the MDR associated with the polymicrobial burn wounds. Recently, it seems that metal oxides can truly be considered as highly efficient inorganic agents with antimicrobial properties. In this study, zinc peroxide NPs (ZnO 2 -NPs) were synthesized using the co-precipitation method. Synthesized ZnO 2 -NPs were characterized by X-ray diffraction, Fourier transformed infrared, transmission electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and ultraviolet-visible spectroscopy. The characterization techniques revealed synthesis of the pure phase of non-agglomerated ZnO 2 -NPs having sizes in the range of 15-25 nm with a transition temperature of 211°C. Antimicrobial activity of ZnO 2 -NPs was determined against MDR Pseudomonas aeruginosa (PA) and Aspergillus niger (AN) strains isolated from burn wound infections. Both strains, PA6 and AN4, were found to be more susceptible strains to ZnO 2 -NPs. In addition, a significant decrease in elastase and keratinase activities was recorded with increased concentrations of ZnO 2 -NPs until 200 µg/mL. ZnO 2 -NPs revealed a significant anti-inflammatory activity against PA6 and AN4 strains as demonstrated by membrane stabilization, albumin denaturation, and proteinase inhibition. Moreover, the results of in vivo histopathology assessment confirmed the potential role of ZnO 2 -NPs in the improvement of skin wound healing in the experimental animal models. Clearly, the synthesized ZnO 2 -NPs have demonstrated a competitive capability as antimicrobial, anti-elastase, anti-keratinase, and anti-inflammatory candidates, suggesting that the ZnO 2 -NPs are promising metal oxides that are potentially valued for biomedical applications.

Biosynthesis, characterization, and evaluation of bioactivities of leaf extract-mediated biocompatible silver nanoparticles from an early tracheophyte, Pteris tripartita Sw.

PubMed Central

Baskaran, Xavierravi; Geo Vigila, Antony Varuvel; Parimelazhagan, Thangaraj; Muralidhara-Rao, Doulathabad; Zhang, Shouzhou

2016-01-01

The objective of the study was to characterize silver nanoparticles (Ag-NPs) and their bioactivities in early tracheophytes (Pteridophyta). Aqueous leaf extract of a critically endangered fern, Pteris tripartita Sw., was used for one-step green synthesis of Ag-NPs. The biosynthesized Ag-NPs were characterized using ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy. Morphologically, the Ag-NPs showed hexagonal, spherical, and rod-shaped structures. Size distributions of Ag-NPs, calculated using Scherrer’s formula, showed an average size of 32 nm. Ag-NPs were studied for in vitro antioxidant, antimicrobial, and in vivo anti-inflammatory activities. Ag-NPs exhibited significant anti-inflammatory activity in carrageenan-induced paw volume tests performed in female Wistar albino rats. Furthermore, Ag-NPs showed significant antimicrobial activity against 12 different microorganisms in three different assays (disk diffusion, time course growth, and minimum inhibitory concentration). This study reports that colloidal Ag-NPs can be synthesized by simple, nonhazardous methods, and that biosynthesized Ag-NPs have significant therapeutic properties. PMID:27895478

Isolation of Lactobacillus salivarius 1077 (NRRL B-50053) and characterization of its bacteriocin and spectra of antimicrobial activity

USDA-ARS?s Scientific Manuscript database

Lactobacillus salivarius 1077 (NRRL B-50053) was isolated from poultry intestinal materials after demonstrating in-vitro anti-Campylobacter jejuni activity. The isolate was then used for in-vitro fermentation. The protein content of the cell-free supernatant from the spent medium was precipitated ...

Leptoglycin: a new Glycine/Leucine-rich antimicrobial peptide isolated from the skin secretion of the South American frog Leptodactylus pentadactylus (Leptodactylidae).

PubMed

Sousa, Juliana C; Berto, Raquel F; Gois, Elicélia A; Fontenele-Cardi, Nauíla C; Honório, José E R; Konno, Katsuhiro; Richardson, Michael; Rocha, Marcos F G; Camargo, Antônio A C M; Pimenta, Daniel C; Cardi, Bruno A; Carvalho, Krishnamurti M

2009-07-01

Antimicrobial peptides are components of innate immunity that is the first-line defense against invading pathogens for a wide range of organisms. Here, we describe the isolation, biological characterization and amino acid sequencing of a novel neutral Glycine/Leucine-rich antimicrobial peptide from skin secretion of Leptodactylus pentadactylus named leptoglycin. The amino acid sequence of the peptide purified by RP-HPLC (C(18) column) was deduced by mass spectrometric de novo sequencing and confirmed by Edman degradation: GLLGGLLGPLLGGGGGGGGGLL. Leptoglycin was able to inhibit the growth of Gram-negative bacteria Pseudomonas aeruginosa, Escherichia coli and Citrobacter freundii with minimal inhibitory concentrations (MICs) of 8 microM, 50 microM, and 75 microM respectively, but it did not show antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus, Micrococcus luteus and Enterococcus faecalis), yeasts (Candida albicans and Candida tropicalis) and dermatophytes fungi (Microsporum canis and Trichophyton rubrum). No hemolytic activity was observed at the 2-200 microM range concentration. The amino acid sequence of leptoglycin with high level of glycine (59.1%) and leucine (36.4%) containing an unusual central proline suggests the existence of a new class of Gly/Leu-rich antimicrobial peptides. Taken together, these results suggest that this natural antimicrobial peptide could be a tool to develop new antibiotics.

Emergence of Antimicrobial-Resistant Escherichia coli of Animal Origin Spreading in Humans.

PubMed

Skurnik, David; Clermont, Olivier; Guillard, Thomas; Launay, Adrien; Danilchanka, Olga; Pons, Stéphanie; Diancourt, Laure; Lebreton, François; Kadlec, Kristina; Roux, Damien; Jiang, Deming; Dion, Sara; Aschard, Hugues; Denamur, Maurice; Cywes-Bentley, Colette; Schwarz, Stefan; Tenaillon, Olivier; Andremont, Antoine; Picard, Bertrand; Mekalanos, John; Brisse, Sylvain; Denamur, Erick

2016-04-01

In the context of the great concern about the impact of human activities on the environment, we studied 403 commensal Escherichia coli/Escherichia clade strains isolated from several animal and human populations that have variable contacts to one another. Multilocus sequence typing (MLST) showed a decrease of diversity 1) in strains isolated from animals that had an increasing contact with humans and 2) in all strains that had increased antimicrobial resistance. A specific B1 phylogroup clonal complex (CC87, Institut Pasteur schema nomenclature) of animal origin was identified and characterized as being responsible for the increased antimicrobial resistance prevalence observed in strains from the environments with a high human-mediated antimicrobial pressure. CC87 strains have a high capacity of acquiring and disseminating resistance genes with specific metabolic and genetic determinants as demonstrated by high-throughput sequencing and phenotyping. They are good mouse gut colonizers but are not virulent. Our data confirm the predominant role of human activities in the emergence of antimicrobial resistance in the environmental bacterial strains and unveil a particular E. coli clonal complex of animal origin capable of spreading antimicrobial resistance to other members of microbial communities. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Enhanced antimicrobial activity and structural transitions of a nanofibrillated cellulose-nisin bio-composite suspension.

PubMed

Weishaupt, Ramon; Heuberger, Lukas; Siqueira, Gilberto; Gutt, Beatrice; Zimmermann, Tanja; Maniura-Weber, Katharina; Salentinig, Stefan; Faccio, Greta

2018-05-16

The occurrence of resistance to antibiotics has posed a high demand for novel strategies to fight bacterial infections. Antimicrobial peptides (AMPs) are a promising alternative to con-ventional antibiotics. However, their poor solubility in water and sensitivity to degradation has limited their application. Here we report the design of a smart, pH-responsive antimicro-bial nanobiocomposite material based on the AMP nisin and oxidized nanofibrillated cellulose (TONFC). Morphological transformations of the nano-scale structure of nisin functionalized TONFC fibrils were discovered at pH values between pH 5.8 and 8.0 using small angle X-ray scattering (SAXS). Complementary zeta potential measurements indicate that electrostatic-attractions between the negatively charged TONFC surface and the positively charged nisin molecules are responsible for the integration of nisin. Contrary, shifting the pH level or in-creasing the ionic strength reduce the nisin binding capacity of TONFC. Biological evaluation studies using a bioluminescence-based reporter strain of Bacillus subtilis and a clinically rele-vant strain of Staphylococcus aureus indicated a significantly higher antimicrobial activity of the TONFC-nisin biocomposite compared to the pure nisin against both strains under physio-logical pH and ionic strength conditions. The in-depth characterization of this new class of an-timicrobial bio-composite material based on nanocellulose and nisin, may guide the rational design of sustainable antimicrobial materials.

Phytochemical characterization, antimicrobial activity and reducing potential of seed oil, latex, machine oil and presscake of Jatropha curcas

PubMed Central

Sharma, Amit Kumar; Gangwar, Mayank; Kumar, Dharmendra; Nath, Gopal; Kumar Sinha, Akhoury Sudhir; Tripathi, Yamini Bhushan

2016-01-01

Objective: This study aims to evaluate the antimicrobial activity, phytochemical studies and thin layer chromatography analysis of machine oil, hexane extract of seed oil and methanol extract of presscake & latex of Jatropha curcas Linn (family Euphorbiaceae). Materials and Methods: J. curcas extracts were subjected to preliminary qualitative phytochemical screening to detect the major phytochemicals followed by its reducing power and content of phenol and flavonoids in different fractions. Thin layer chromatography was also performed using different solvent systems for the analysis of a number of constituents in the plant extracts. Antimicrobial activity was evaluated by the disc diffusion method, while the minimum inhibitory concentration, minimum bactericidal concentration and minimum fungicidal concentration were calculated by micro dilution method. Results: The methanolic fraction of latex and cake exhibited marked antifungal and antibacterial activities against Gram-positive and Gram-negative bacteria. Phytochemical analysis revealed the presence of alkaloids, saponins, tannins, terpenoids, steroids, glycosides, phenols and flavonoids. Reducing power showed dose dependent increase in concentration compared to standard Quercetin. Furthermore, this study recommended the isolation and separation of bioactive compounds responsible for the antibacterial activity which would be done by using different chromatographic methods such as high-performance liquid chromatography (HPLC), GC-MS etc. Conclusion: The results of the above study suggest that all parts of the plants possess potent antibacterial activity. Hence, it is important to isolate the active principles for further testing of antimicrobial and other biological efficacy. PMID:27516977

Phytochemical characterization, antimicrobial activity and reducing potential of seed oil, latex, machine oil and presscake of Jatropha curcas.

PubMed

Sharma, Amit Kumar; Gangwar, Mayank; Kumar, Dharmendra; Nath, Gopal; Kumar Sinha, Akhoury Sudhir; Tripathi, Yamini Bhushan

2016-01-01

This study aims to evaluate the antimicrobial activity, phytochemical studies and thin layer chromatography analysis of machine oil, hexane extract of seed oil and methanol extract of presscake & latex of Jatropha curcas Linn (family Euphorbiaceae). J. curcas extracts were subjected to preliminary qualitative phytochemical screening to detect the major phytochemicals followed by its reducing power and content of phenol and flavonoids in different fractions. Thin layer chromatography was also performed using different solvent systems for the analysis of a number of constituents in the plant extracts. Antimicrobial activity was evaluated by the disc diffusion method, while the minimum inhibitory concentration, minimum bactericidal concentration and minimum fungicidal concentration were calculated by micro dilution method. The methanolic fraction of latex and cake exhibited marked antifungal and antibacterial activities against Gram-positive and Gram-negative bacteria. Phytochemical analysis revealed the presence of alkaloids, saponins, tannins, terpenoids, steroids, glycosides, phenols and flavonoids. Reducing power showed dose dependent increase in concentration compared to standard Quercetin. Furthermore, this study recommended the isolation and separation of bioactive compounds responsible for the antibacterial activity which would be done by using different chromatographic methods such as high-performance liquid chromatography (HPLC), GC-MS etc. The results of the above study suggest that all parts of the plants possess potent antibacterial activity. Hence, it is important to isolate the active principles for further testing of antimicrobial and other biological efficacy.

Green synthesis, antimicrobial and cytotoxic effects of silver nanoparticles using Eucalyptus chapmaniana leaves extract.

PubMed

Sulaiman, Ghassan Mohammad; Mohammed, Wasnaa Hatif; Marzoog, Thorria Radam; Al-Amiery, Ahmed Abdul Amir; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

2013-01-01

To synthesize silver nanopaticles from leaves extract of Eucalyptus chapmaniana (E. chapmaniana) and test the antimicrobial of the nanoparticles against different pathogenic bacteria, yeast and its toxicity against human acute promyelocytic leukemia (HL-60) cell line. Ten milliliter of leaves extract was mixed with 90 mL of 0.01 mmol/mL or 0.02 mmol/mL aqueous AgNO3 and exposed to sun light for 1 h. A change from yellowish to reddish brown color was observed. Characterization using UV-vis spectrophotometery and X-ray diffraction analysis were performed. Antimicrobial activity against six microorganisms was tested using well diffusion method and cytoxicity test using 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a yellow tetrazole was obtained on the human leukemia cell line (HL-60). UV-vis spectral analysis showed silver surface plasmon resonance band at 413 nm. X-ray diffraction showed that the particles were crystalline in nature with face centered cubic structure of the bulk silver with broad beaks at 38.50° and 44.76°. The synthesized silver nanoparticles efficiently inhibited various pathogenic organisms and reduced viability of the HL-60 cells in a dose-dependent manner. It has been demonstrated that the extract of E. chapmaniana leaves are capable of producing silver nanoparticles extracellularly and the Ag nanoparticles are quite stable in solution. Further studies are needed to fully characterize the toxicity and the mechanisms involved with the antimicrobial and anticancer activity of these particles.

Dittrichia graveolens (L.) Greuter Essential Oil: Chemical Composition, Multivariate Analysis, and Antimicrobial Activity.

PubMed

Mitic, Violeta; Stankov Jovanovic, Vesna; Ilic, Marija; Jovanovic, Olga; Djordjevic, Aleksandra; Stojanovic, Gordana

2016-01-01

The chemical composition and in vitro antimicrobial activities of Dittrichia graveolens (L.) Greuter essential oil was studied. Moreover, using agglomerative hierarchical cluster (AHC) and principal component analyses (PCA), the interrelationships of the D. graveolens essential-oil profiles characterized so far (including the sample from this study) were investigated. To evaluate the chemical composition of the essential oil, GC-FID and GC/MS analyses were performed. Altogether, 54 compounds were identified, accounting for 92.9% of the total oil composition. The D. graveolens oil belongs to the monoterpenoid chemotype, with monoterpenoids comprising 87.4% of the totally identified compounds. The major components were borneol (43.6%) and bornyl acetate (38.3%). Multivariate analysis showed that the compounds borneol and bornyl acetate exerted the greatest influence on the spatial differences in the composition of the reported oils. The antimicrobial activity against five bacterial and one fungal strain was determined using a disk-diffusion assay. The studied essential oil was active only against Gram-positive bacteria. Copyright © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

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

PubMed

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

2003-09-11

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

Characterization of Essential Oils Obtained from Abruzzo Autochthonous Plants: Antioxidant and Antimicrobial Activities Assessment for Food Application

PubMed Central

Pellegrini, Marika; Chaves-López, Clemencia; Mazzarrino, Giovanni; D’Amato, Serena; Lo Sterzo, Claudio

2018-01-01

In the present study, the essential oils (EOs) of some officinal plants from Abruzzo territory (Italy) were evaluated for their antimicrobial and antioxidant activities and their volatile fraction chemical characterization. The EOs were extracted from Rosmarinus officinalis, Origanum vulgare, Salvia officinalis, Mentha piperita, Allium sativum, Foeniculum vulgare, Satureja montana, Thymus vulgaris and Coriandrum sativum seeds. The antimicrobial activity was screened against thirteen Gram-positive and Gram-negative strains to determine the Minimal Inhibitory Concentration (MIC). The total phenolic content (TPC) and the antioxidant capacity (AOC) were assessed by means of Folin-Ciocâlteu method, and Trolox Equivalent Antioxidant Capacity with 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (TEAC/ABTS), Ferric Reducing Antioxidant Power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays respectively. Among the nine EOs tested, T. vulgaris, S. montana, O. vulgare and C. sativum EOs showed MIC values ranging from 0.625 to 5 μL/mL. The AOC and TPC results for these species were also interesting. The major components for these EOs were thymol for T. vulgaris (44%) and O. vulgare (40%), linalool (77%) for C. sativum, and carvacrol for S. montana (54%). The results allowed the study to establish that these EOs are good candidates for potential application as biopreservatives in foods and/or food manufacture environments. PMID:29393893

Evaluation of the in vitro antimicrobial activity of an ethanol extract of Brazilian classified propolis on strains of Staphylococcus aureus

PubMed Central

Pamplona-Zomenhan, Lucila Coelho; Pamplona, Beatriz Coelho; da Silva, Cely Barreto; Marcucci, Maria Cristina; Mimica, Lycia Mara Jenné

2011-01-01

Staphylococcus aureus (S. aureus) is one of the most frequent causes of hospital acquired infections. With the increase in multiple drug resistant strains, natural products such as propolis are a stratagem for new product discovery. The aims of this study were: to determine the in vitro antimicrobial activity of an ethanol extract of propolis; to define the MIC50 and MIC90 (Minimal Inhibitory Concentration – MIC) against 210 strains of S. aureus; to characterize a crude sample of propolis and the respective ethanol extract as to the presence of predetermined chemical markers. The agar dilution method was used to define the MIC and the high performance liquid chromatography (HPLC) method was used to characterize the samples of propolis. MIC results ranged from 710 to 2,850 µg/mL. The MIC50 and MIC90 for the 210 strains as well as the individual analysis of American Type Culture Collection (ATCC) strains of Methicillin-susceptible Staphylococcus aureus (MSSA) and Methicillin-resistant Staphylococcus aureus (MRSA) were both 1,420 µg/mL. Based on the chromatographic analysis of the crude sample and ethanol extracted propolis, it was concluded that propolis was a mixture of the BRP (SP/MG) and BRP (PR) types. The results obtained confirm an antimicrobial activity in relation to the strains of the S. aureus tested. PMID:24031749

Commiphora leptophloeos Phytochemical and Antimicrobial Characterization

PubMed Central

de Souza Pereira, Jorge J.; Pereira, Aline de P. C.; Jandú, Jannyson J. B.; da Paz, Josinete A.; Crovella, Sergio; dos Santos Correia, Maria T.; de Azevêdo Silva, Jaqueline

2017-01-01

Commiphora leptophloeos is a plant specie usually known for its medicinal purposes in local communities in Northeast Brazil. In order to evaluate its therapeutic potential, we aimed to determine the phytochemical and antimicrobial properties of C. leptophloeos extracts. Thin Layer Chromatography (TLC) was able to detect the presence of phenolic compounds, flavonoids and reducing sugars. Three phenolic compounds were identified by HPLC and described as Gallic, Chlorogenic and Protocatechuic acids. On the other hand, H1NMR analysis revealed the presence of hinokinin, a bioactive lignan further characterized in the present work. The minimum inhibitory concentration (MIC) values for hinokinin ranged from 0.0485 to 3.125 mg/mL in different S. aureus clinical isolates and showed a bactericidal activity against MRSA isolated from blood (MMC 0.40 mg/mL) and postoperative secretion (MMC = 3.125 mg/mL). C. leptophloeos extracts also showed antimicrobial activity against Mycobacterium species such as M. smegmatis (MIC = 12.5 mg/mL) and M. tuberculosis (MIC = 52 mg/mL). Additionally, we determined the toxicity of C. leptophloeos by in vitro HC50 tests with hemolytic activity detected of 313 ± 0.5 μg/mL. Our results showed that C. leptophloeos possesses inhibitory properties against MRSA as well as several other clinically important microorganisms. Furthermore, the present work is the first report of the presence of hinokinin in Commiphora genus. PMID:28174564

Chitosan-Iron Oxide Coated Graphene Oxide Nanocomposite Hydrogel: A Robust and Soft Antimicrobial Biofilm.

PubMed

Konwar, Achyut; Kalita, Sanjeeb; Kotoky, Jibon; Chowdhury, Devasish

2016-08-17

We report a robust biofilm with antimicrobial properties fabricated from chitosan-iron oxide coated graphene oxide nanocomposite hydrogel. For the first time, the coprecipitation method was used for the successful synthesis of iron oxide coated graphene oxide (GIO) nanomaterial. After this, films were fabricated by the gel-casting technique aided by the self-healing ability of the chitosan hydrogel network system. Both the nanomaterial and the nanocomposite films were characterized by techniques such as scanning electron microscopy, FT-IR spectroscopy, X-ray diffraction, and vibrating sample magnetometry. Measurements of the thermodynamic stability and mechanical properties of the films indictaed a significant improvement in their thermal and mechanical properties. Moreover, the stress-strain profile indicated the tough nature of the nanocomposite hydrogel films. These improvements, therefore, indicated an effective interaction and good compatibility of the GIO nanomaterial with the chitosan hydrogel matrix. In addition, it was also possible to fabricate films with tunable surface properties such as hydrophobicity simply by varying the loading percentage of GIO nanomaterial in the hydrogel matrix. Fascinatingly, the chitosan-iron oxide coated graphene oxide nanocomposite hydrogel films displayed significant antimicrobial activities against both Gram-positive and Gram-negative bacterial strains, such as methicillin-resistant Staphylococcus aureus, Staphylococcus aureus, and Escherichia coli, and also against the opportunistic dermatophyte Candida albicans. The antimicrobial activities of the films were tested by agar diffusion assay and antimicrobial testing based on direct contact. A comparison of the antimicrobial activity of the chitosan-GIO nanocomposite hydrogel films with those of individual chitosan-graphene oxide and chitosan-iron oxide nanocomposite films demonstrated a higher antimicrobial activity for the former in both types of tests. In vitro hemolysis potentiality tests and MTT assays of the nanocomposite films indicated a noncytotoxic nature of the films, which conveyed the possibility of potential applications of these soft and tough films in biomedical as well as in the food industry.

Use of Lactobacillus plantarum Strains as a Bio-Control Strategy against Food-Borne Pathogenic Microorganisms

PubMed Central

Arena, Mattia Pia; Silvain, Amandine; Normanno, Giovanni; Grieco, Francesco; Drider, Djamel; Spano, Giuseppe; Fiocco, Daniela

2016-01-01

Lactobacillus plantarum is one of the most versatile species extensively used in the food industry both as microbial starters and probiotic microorganisms. Several L. plantarum strains have been shown to produce different antimicrobial compounds such as organic acids, hydrogen peroxide, diacetyl, and also bacteriocins and antimicrobial peptides, both denoted by a variable spectrum of action. In recent decades, the selection of microbial molecules and/or bacterial strains able to produce antagonistic molecules to be used as antimicrobials and preservatives has been attracting scientific interest, in order to eliminate or reduce chemical additives, because of the growing attention of consumers for healthy and natural food products. The aim of this work was to investigate the antimicrobial activity of several food-isolated L. plantarum strains, analyzed against the pathogenic bacteria Listeria monocytogenes, Salmonella Enteritidis, Escherichia coli O157:H7 and Staphylococcus aureus. Antagonistic activity was assayed by agar spot test and revealed that strain L. plantarum 105 had the strongest ability to contrast the growth of L. monocytogenes, while strains L. plantarum 106 and 107 were the most active microorganisms against E. coli O157:H7. The antimicrobial ability was also screened by well diffusion assay and broth micro-dilution method using cell-free supernatants (CFS) from each Lactobacillus strain. Moreover, the chemical nature of the molecules released in the CFS, and possibly underlying the antagonistic activity, was preliminary characterized by exposure to different constraints such as pH neutralization, heating, catalase, and proteinase treatments. Our data suggest that the ability of L. plantarum cultures to contrast pathogens growth in vitro depends, at least in part, on a pH-lowering effect of supernatants and/or on the presence of organic acids. Cluster analysis was performed in order to group L. plantarum strains according to their antimicrobial effect. This study emphasizes the tempting use of the tested L. plantarum strains and/or their CFS as antimicrobial agents against food-borne pathogens. PMID:27148172

Peptidomic approach identifies cruzioseptins, a new family of potent antimicrobial peptides in the splendid leaf frog, Cruziohyla calcarifer.

PubMed

Proaño-Bolaños, Carolina; Zhou, Mei; Wang, Lei; Coloma, Luis A; Chen, Tianbao; Shaw, Chris

2016-09-02

Phyllomedusine frogs are an extraordinary source of biologically active peptides. At least 8 families of antimicrobial peptides have been reported in this frog clade, the dermaseptins being the most diverse. By a peptidomic approach, integrating molecular cloning, Edman degradation sequencing and tandem mass spectrometry, a new family of antimicrobial peptides has been identified in Cruziohyla calcarifer. These 15 novel antimicrobial peptides of 20-32 residues in length are named cruzioseptins. They are characterized by having a unique shared N-terminal sequence GFLD- and the sequence motifs -VALGAVSK- or -GKAAL(N/G/S) (V/A)V- in the middle of the peptide. Cruzioseptins have a broad spectrum of antimicrobial activity and low haemolytic effect. The most potent cruzioseptin was CZS-1 that had a MIC of 3.77μM against the Gram positive bacterium, Staphylococcus aureus and the yeast Candida albicans. In contrast, CZS-1 was 3-fold less potent against the Gram negative bacterium, Escherichia coli (MIC 15.11μM). CZS-1 reached 100% haemolysis at 120.87μM. Skin secretions from unexplored species such as C. calcarifer continue to demonstrate the enormous molecular diversity hidden in the amphibian skin. Some of these novel peptides may provide lead structures for the development of a new class of antibiotics and antifungals of therapeutic use. Through the combination of molecular cloning, Edman degradation sequencing, tandem mass spectrometry and MALDI-TOF MS we have identified a new family of 15 antimicrobial peptides in the skin secretion of Cruziohyla calcarifer. The novel family is named "Cruzioseptins" and contains cationic amphipathic peptides of 20-32 residues. They have a broad range of antimicrobial activity that also includes effective antifungals with low haemolytic activity. Therefore, C. calcarifer has proven to be a rich source of novel peptides, which could become leading structures for the development of novel antibiotics and antifungals of clinical application. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis, spectral characterization and in vitro antimicrobial activity of some new azopyridine derivatives

NASA Astrophysics Data System (ADS)

Abuo-Melha, Hanaa; Fadda, A. A.

2012-04-01

A series of arylpicolino and/or isonicotinohydrazonyl cyanide 2a-d and 4a-f were prepared by coupling the approprite aryl diazonium salt with 2-cyanomethyl and/or 4-cyanomethyl-pyridine, respectively. These compounds were characterized by analytical and spectral analyses and screened for their antibacterial activity against Gram-positive bacteria, Gram-negative bacteria and antifungal activity. Among the synthesized compounds, N'-(4-phenyldiazenyl)phenylisonicotinohydrazonyl cyanide 4f showed a significant activity toward both Gram-positive, Gram-negative bacteria and exhibit the most potent in vitro antifungal with MIC's (625 μg/mL) against Aspergillus nieger.

Optical properties and antimicrobial effects of silver nanoparticles synthesized by femtosecond laser photoreduction

NASA Astrophysics Data System (ADS)

dos Santos Courrol, Daniella; Regina Borges Lopes, Carla; da Silva Cordeiro, Thiago; Regina Franzolin, Marcia; Dias Vieira Junior, Nilson; Elgul Samad, Ricardo; Coronato Courrol, Lilia

2018-07-01

Silver nanoparticles exhibit a powerful antimicrobial action showing a pronounced potential to be widely used against drug resistance bacteria. The present work describes the optical properties and antimicrobial effect of silver nanoparticles produced by femtosecond laser photoreduction of AgNO3 in the presence of tryptophan water solution. The advantages of this method are the absence of hazardous chemical reducing agents in the solution, and the versatile dimensional control achieved. The synthesized silver nanoparticles were characterized by absorption and fluorescence spectroscopy and their antibacterial activity were determined by monitoring the cell viability of Escherichia coli. The effects of the silver nanoparticles concentration and laser parameters (exposure time and pulse energy), on the formation of the nanoparticles, and its influence on the bacteria growth inhibition were studied. The prepared silver nanoparticles exhibited suitable antimicrobial properties. The results demonstrated that the nanoparticles concentration plays an important role in their bactericidal efficacy. The increase in the laser energy caused an increase in E. coli growth inhibition. Irradiations with energies around 300 μJ for 60 min presented high antimicrobial activity due to the presence of kynurenine, sub product of tryptophan photolysis. The first-time formation mechanism of tryptophan silver nanoparticles in high optical intensities was also discussed.

Starch-based polyurethane/CuO nanocomposite foam: Antibacterial effects for infection control.

PubMed

Ashjari, Hamid Reza; Dorraji, Mir Saeed Seyed; Fakhrzadeh, Vahid; Eslami, Hosein; Rasoulifard, Mohammad Hossein; Rastgouy-Houjaghan, Mehrdad; Gholizadeh, Pourya; Kafil, Hossein Samadi

2018-05-01

In the present study, a new method for the synthesis of the open cell flexible polyurethane foams (PUFs) was developed by using starch powder and the modification of closed cell foam formulation. Starch is the second largest polymeric carbohydrate as a macromolecule on this planet with a large number of glucose units. Copper oxide nanoparticles (CuO NPs) were synthesized by thermal degradation method at different temperatures of 400, 600 and 800 °C as antimicrobial agents. The antimicrobial activity of CuO NPs and commercial CuO powder against the main causes of hospital infections were tested. CuO 600 was the most effective antimicrobial agent and enhanced polymer matrix tensile strength with starch powder as new polyurethane foams (PUFs) cell opener with high tensile strength. The effects of parameters on tensile strength were optimized using response surface methodology (RSM). CuO NPs and PUF had optimal conditions and were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Foam synthesized at the optimal conditions had an open cell structure with high tensile strength and efficient antimicrobial activity that made them suitable to be used as an antimicrobial hospital mattress to control hospital infections. Copyright © 2018 Elsevier B.V. All rights reserved.

Antimicrobial properties of zeolite-X and zeolite-A ion-exchanged with silver, copper, and zinc against a broad range of microorganisms.

PubMed

Demirci, Selami; Ustaoğlu, Zeynep; Yılmazer, Gonca Altın; Sahin, Fikrettin; Baç, Nurcan

2014-02-01

Zeolites are nanoporous alumina silicates composed of silicon, aluminum, and oxygen in a framework with cations, water within pores. Their cation contents can be exchanged with monovalent or divalent ions. In the present study, the antimicrobial (antibacterial, anticandidal, and antifungal) properties of zeolite type X and A, with different Al/Si ratio, ion exchanged with Ag(+), Zn(2+), and Cu(2+) ions were investigated individually. The study presents the synthesis and manufacture of four different zeolite types characterized by scanning electron microscopy and X-ray diffraction. The ion loading capacity of the zeolites was examined and compared with the antimicrobial characteristics against a broad range of microorganisms including bacteria, yeast, and mold. It was observed that Ag(+) ion-loaded zeolites exhibited more antibacterial activity with respect to other metal ion-embedded zeolite samples. The results clearly support that various synthetic zeolites can be ion exchanged with Ag(+), Zn(2+), and Cu(2+) ions to acquire antimicrobial properties or ion-releasing characteristics to provide prolonged or stronger activity. The current study suggested that zeolite formulations could be combined with various materials used in manufacturing medical devices, surfaces, textiles, or household items where antimicrobial properties are required.

Extracellular facile biosynthesis, characterization and stability of gold nanoparticles by Bacillus licheniformis.

PubMed

Singh, Sneha; Vidyarthi, Ambarish Sharan; Nigam, Vinod Kumar; Dev, Abhimanyu

2014-02-01

The development of a reliable, eco-friendly process for synthesis of gold nanoparticles (AuNPs) has gained impetus in recent years to counter the drawbacks of chemical and physical methods. This study illustrates simple, green synthesis of AuNPs in vitro using cell lysate supernatant (CLS) of non-pathogenic bacteria and to investigate its potential antimicrobial activity. Gold nanoparticles were synthesized by the reduction of precursor AuCl4- ions using the CLS of Bacillus licheniformis at 37°C upon 24 h of incubation. The nanoparticles were characterized for their morphology, particle size, optical absorption, zeta potential, and stability. Further the antimicrobial activity was assayed using cup-plate method. The process of biosynthesis was extracellular and the gold ions were reduced to stable nanogold of average size 38 nm. However, upon storage of AuNPs for longer duration at room temperature stability was influenced in terms of increase in particle size and decrease in zeta potential with respect to as synthesized nanoparticles. SEM micrographs revealed the spherical shape of AuNPs and EDX analysis confirmed the presence of gold in the sample. Also clear zone of inhibition was observed against Bacilllus subtilis MTCC 8364, Pseudomonas aeruginosa MTCC 7925, and Escherichia coli MTCC 1698 confirming the antimicrobial activity of AuNPs. The bioprocess under study was simple and less time consuming as compared to other methods as the need for harvesting AuNPs from within the microbial cells via downstream process will be eliminated. Nanoparticles exhibited good stability even in absence of external stabilizing agents. AuNPs showed good antimicrobial activity against several Gram-negative and Gram-positive pathogenic bacteria. The extracellular biosynthesis from CLS may serve as a suitable alternative for large scale synthesis of gold nanoparticles in vitro. The synthesis from lysed bacterial cell strongly suggests that exposure of microbial whole cells to the gold solution for nanoparticle formation is not necessary and that microorganism even in lysed state retained its bioreduction potential. Further the potential of biologically synthesized AuNPs as antimicrobial agents will be of great commercial importance.

Preparation and characterization of antibacterial orthodontic resin containing silver nanoparticles

NASA Astrophysics Data System (ADS)

Lee, Sang Jin; Heo, Min; Lee, Donghyun; Han, Seungheui; Moon, Ji-Hoi; Lim, Ho-Nam; Kwon, Il Keun

2018-02-01

In this study, we developed a hybrid dental resin containing silver nanoparticle (AgNPs) to eliminate periodontal disease causing bacteria such as streptococcus mutans (S. mutans) and streptococcus sobrinus (S. sobrinus). The silver nanoparticles enables the resin to prevent oral pathogen growth during orthodontic therapy. First, AgNPs were directly synthesized in dimethylformamide (DMF) solvent with a capping agent. Second, pure orthodontic primer was mixed with the synthesized AgNPs solvent-slurry followed by photocuring. The resultant material was characterized by physicochemical characterization. Finally, an in vitro antimicrobial test was carried out. The results showed that the AgNPs were fully synthesized and clearly embedded in dental resin. In the bacterial test, the dental resin containing AgNPs showed potent antimicrobial activity against two kinds of bacteria. In conclusion, our methodology may allow for the generation of a wide range of dental resin and composite products which inhibit periodontitis causing bacteria.

Investigation of antibacterial activity of Bacillus spp. isolated from the feces of Giant Panda and characterization of their antimicrobial gene distributions.

PubMed

Zhou, Ziyao; Zhou, Xiaoxiao; Zhong, Zhijun; Wang, Chengdong; Zhang, Hemin; Li, Desheng; He, Tingmei; Li, Caiwu; Liu, Xuehan; Yuan, Hui; Ji, Hanli; Luo, Yongjiu; Gu, Wuyang; Fu, Hualin; Peng, Guangneng

2014-12-01

Bacillus group is a prevalent community of Giant Panda's intestinal flora, and plays a significant role in the field of biological control of pathogens. To understand the diversity of Bacillus group from the Giant Panda intestine and their functions in maintaining the balance of the intestinal microflora of Giant Panda, this study isolated a significant number of strains of Bacillus spp. from the feces of Giant Panda, compared the inhibitory effects of these strains on three common enteric pathogens, investigated the distributions of six universal antimicrobial genes (ituA, hag, tasA, sfp, spaS and mrsA) found within the Bacillus group by PCR, and analyzed the characterization of antimicrobial gene distributions in these strains using statistical methods. The results suggest that 34 strains of Bacillus spp. were isolated which has not previously been detected at such a scale, these Bacillus strains could be classified into five categories as well as an external strain by 16S rRNA; Most of Bacillus strains are able to inhibit enteric pathogens, and the antimicrobial abilities may be correlated to their categories of 16S rRNA; The detection rates of six common antimicrobial genes are between 20.58 %(7/34) and 79.41 %(27/34), and genes distribute in three clusters in these strains. We found that the antimicrobial abilities of Bacillus strains can be one of the mechanisms by which Giant Panda maintains its intestinal microflora balance, and may be correlated to their phylogeny.

Photo-activated porphyrin in combination with antibiotics: therapies against Staphylococci

PubMed Central

Dastgheyb, Sana S.; Eckmann, David M.; Composto, Russell J.

2013-01-01

Staphylococcal infections have become difficult to treat due to antibiotic insensitivity and resistance. Antimicrobial combination therapies may minimize acquisition of resistance and photodynamic therapy is an attractive candidate for these combinations. In this manuscript, we explore combined use of antibiotics and meso-tetra (4-aminophenyl) porphine (TAPP), a cationic porphyrin, for treatment of Staphylococcus aureus contamination. We characterize the antimicrobial activity of photoactivated TAPP and show that activity is largely lost in the presence of a radical scavenger. Importantly, TAPP can be reactivated with continued, albeit attenuated, antibacterial activity. We then show that the antimicrobial activity of illuminated TAPP is additive with chloramphenicol and tobramycin for Staphylococcus aureus and Escherichia coli, and synergistic for MRSA and Staphylococcus epidermidis. Chloramphenicol + methylene blue, another photosensitizer, also show additivity against Staphylococcus aureus. In contrast, ceftriaxone and vancomycin do not strongly augment the low level effects of TAPP against S. aureus. Eukaryotic cells exhibit a dose-dependent toxicity with illuminated TAPP. Our results suggest that even sub-minimum inhibitory concentration levels of photo-activated TAPP could be used to boost the activity of waning antibiotics. This may play an important role in treatments reliant on antibiotic controlled release systems where augmentation with photo-active agents could extend their efficacy. PMID:24148969

Antimicrobial Evaluation of Mangiferin Analogues

PubMed Central

Singh, S. K.; Kumar, Y.; Kumar, S. Sadish; Sharma, V. K.; Dua, K.; Samad, A.

2009-01-01

The naturally occurring xanthone glycoside mangiferin has been isolated by column chromatography from the ethanol extract of stem bark of Mangifera indica. Mangiferin was further converted to 5-(N-phenylaminomethyleno)mangiferin, 5-(N-p-chlorophenylaminomethyleno) mangiferin, 5-(N-2-methylphenylaminomethyleno) mangiferin, 5-(N-p-methoxyphenylaminomethyleno) mangiferin, 5-(N, N-diphenylaminomethyleno) mangiferin, 5-(N--napthylaminomethyleno) mangiferin and 5-(N-4-methylphenylaminomethyleno) mangiferin. Mangiferin and its analogues were characterized by melting point and Rf value determination and through spectral technique like UV, IR, and NMR spectral analysis. The synthesized compounds were screened for antimicrobial activity. PMID:20490307

Solvent-free synthesis, spectral correlations and antimicrobial activities of some aryl E 2-propen-1-ones

NASA Astrophysics Data System (ADS)

Sathiyamoorthi, K.; Mala, V.; Sakthinathan, S. P.; Kamalakkannan, D.; Suresh, R.; Vanangamudi, G.; Thirunarayanan, G.

2013-08-01

Totally 38 aryl E 2-propen-1-ones including nine substituted styryl 4-iodophenyl ketones have been synthesised using solvent-free SiO2-H3PO4 catalyzed Aldol condensation between respective methyl ketones and substituted benzaldehydes under microwave irradiation. The yields of the ketones are more than 80%. The synthesised chalcones were characterized by their analytical, physical and spectroscopic data. The spectral frequencies of synthesised substituted styryl 4-iodophenyl ketones have been correlated with Hammett substituent constants, F and R parameters using single and multi-linear regression analysis. The antimicrobial activities of 4-iodophenyl chalcones have been studied using Bauer-Kirby method.

Synthesis, spectral studies, antimicrobial, antioxidant and insect antifeedant activities of some 9 H-fluorene-2-yl keto-oxiranes

NASA Astrophysics Data System (ADS)

Thirunarayanan, G.; Vanangamudi, G.

2011-10-01

Thirteen ee (α S, β R) 9 H-fluorene-2-yl keto-oxiranes (2-(9 H)-fluorene-4-yl[3-(substituted phenyl)oxiran-2-yl]methanones) have been synthesized by phase transfer catalysed epoxidation of 9 H-fluorene-2-yl chalcones. The yields of oxiranes are more than 95%. The synthesized oxiranes have been characterized by IR, 1H, 13C and GC-MS spectral data. The spectral data are correlated with Hammett substituent constants and Swain-Lupton parameters. From the regression analysis, the effect of substituents on the group frequencies has been predicted. The antimicrobial, antioxidant and insect antifeedant activities of all the synthesized oxiranes have been studied.

Preparation of zeolite-A/chitosan hybrid composites and their bioactivities and antimicrobial activities.

PubMed

Yu, Liang; Gong, Jie; Zeng, Changfeng; Zhang, Lixiong

2013-10-01

Zeolite-A/chitosan hybrid composites with zeolite contents of 20-55 wt.% were prepared by in situ transformation of silica/chitosan mixtures in a sodium aluminate alkaline solution through impregnation-gelation-hydrothermal synthesis. The products were characterized by X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mercury penetration porosimetry. Their in vitro bioactivities were examined using as-synthesized and Ca(2+)-exchanged hybrid composites in simulated body fluid (SBF) for hydroxyapatite (HAP) growth. Their antimicrobial activities for Escherichia coli (E. coli) in trypticase soy broth (TSB) were evaluated using Ag(+)-exchanged hybrid composites. The zeolite-A/chitosan hybrid composites could be prepared as various shapes, including cylinders, plates and thin films. They possessed macropores with pore sizes ranging from 100 to 300 μm and showed compressive mechanical strength as high as 3.2 MPa when the zeolite content was 35 wt.%. Fast growth on the Ca(2+)-exchanged hybrid composites was observed with the highest weight gain of 51.4% in 30 days. The 35 wt.% Ag(+)-exchanged hybrid composite showed the highest antimicrobial activity, which could reduce the 9×10(6) CFU mL(-1)E. coli concentration to zero within 4h of incubation time with the Ag(+)-exchanged hybrid composite amount of 0.4 g L(-1). The bioactivity and antimicrobial activity could be combined by ion-exchanging the composites first with Ca(2+) and then with Ag(+). These zeolite-A/chitosan hybrid composites have potential applications on tissue engineering and antimicrobial food packaging. Copyright © 2013 Elsevier B.V. All rights reserved.

Brazilian Kefir-Fermented Sheep's Milk, a Source of Antimicrobial and Antioxidant Peptides.

PubMed

de Lima, Meire Dos Santos Falcão; da Silva, Roberto Afonso; da Silva, Milena Fernandes; da Silva, Paulo Alberto Bezerra; Costa, Romero Marcos Pedrosa Brandão; Teixeira, José António Couto; Porto, Ana Lúcia Figueiredo; Cavalcanti, Maria Taciana Holanda

2017-12-28

Fermented milks are a source of bioactive peptides and may be considered as functional foods. Among these, sheep's milk fermented with kefir has not been widely studied and its most relevant properties need to be more thoroughly characterized. This research study is set out to investigate and evaluate the antioxidant and antimicrobial properties of peptides from fermented sheep's milk in Brazil when produced by using kefir. For this, the chemical and microbiological composition of the sheep's milk before and after the fermentation was evaluated. The changes in the fermented milk and the peptides extracted before the fermentation and in the fermented milk during its shelf life were verified. The antimicrobial and antioxidant activities of the peptides from the fermented milk were evaluated and identified according to the literature. The physicochemical properties and mineral profile of the fermented milk were like those of fresh milk. The peptide extract presented antimicrobial activity and it was detected that 13 of the 46 peptides were able to inhibit the growth of pathogenic microorganisms. A high antioxidant activity was observed in the peptides extracted from fermented milk (3.125 mg/mL) on the 28th day of storage. Two fractions displayed efficient radical scavenging properties by DPPH and ABTS methods. At least 11 peptides distributed in the different fractions were identified by tandem mass spectrometry. This sheep's milk fermented by Brazilian kefir grains, which has antioxidant and antimicrobial activities and probiotic microorganisms, is a good candidate for further investigation as a source for bioactive peptides. The fermentation process was thus a means by which to produce potential bioactive peptides.

Selective advantages of two major clones of carbapenem-resistant Pseudomonas aeruginosa isolates (CC235 and CC641) from Korea: antimicrobial resistance, virulence and biofilm-forming activity.

PubMed

Lee, Ji-Young; Peck, Kyong Ran; Ko, Kwan Soo

2013-07-01

The characteristics of carbapenem-resistant P. aeruginosa (CRPA) isolates from Korea were investigated. Two major clones, clonal complex (CC) 235 and CC641, were identified. CC235, an important international clone, might have been imported recently in Korea as this clone displayed a homogeneous genotype, oprD mutation and antimicrobial resistance profile. While 13 ST235 isolates harboured the blaIMP-6 gene, which conferred high-level meropenem resistance, CC641 isolates showed high biofilm-forming activity. CC235 and CC641 isolates showed distinct distribution of ferripyoverdine receptor type and virulence markers. While all CC235 isolates were of the fpvAIIb type and exoS(-)/exoU(+), CC641 isolates were exoS(+)/exoU(-), and all but one showed the fpvAIII type. CC235 and CC641 isolates were also characterized by different extracellular protease activity: staphylolysin and elastase activities in CC235 and CC641, respectively. Two major CRPA clones in Korea seem to be predominant, reflecting their selective advantage by virtue of antimicrobial resistance, virulence and biofilm-forming activity.

Benzofuranyl Esters: Synthesis, Crystal Structure Determination, Antimicrobial and Antioxidant Activities.

PubMed

Kumar, C S Chidan; Then, Li Yee; Chia, Tze Shyang; Chandraju, Siddegowda; Win, Yip-Foo; Sulaiman, Shaida Fariza; Hashim, Nurul Shafiqah; Ooi, Kheng Leong; Quah, Ching Kheng; Fun, Hoong-Kun

2015-09-11

A series of five new 2-(1-benzofuran-2-yl)-2-oxoethyl 4-(un/substituted)benzoates 4(a-e), with the general formula of C₈H₅O(C=O)CH₂O(C=O)C₆H₄X, X = H, Cl, CH₃, OCH₃ or NO₂, was synthesized in high purity and good yield under mild conditions. The synthesized products 4(a-e) were characterized by FTIR, ¹H-, (13)C- and ¹H-(13)C HMQC NMR spectroscopic analysis and their 3D structures were confirmed by single-crystal X-ray diffraction studies. These compounds were screened for their antimicrobial and antioxidant activities. The tested compounds showed antimicrobial ability in the order of 4b < 4a < 4c < 4d < 4e and the highest potency with minimum inhibition concentration (MIC) value of 125 µg/mL was observed for 4e. The results of antioxidant activities revealed the highest activity for compound 4e (32.62% ± 1.34%) in diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, 4d (31.01% ± 4.35%) in ferric reducing antioxidant power (FRAP) assay and 4a (27.11% ± 1.06%) in metal chelating (MC) activity.

Synthesis, characterization and biological activity of Schiff bases based on chitosan and arylpyrazole moiety.

PubMed

Salama, Hend E; Saad, Gamal R; Sabaa, Magdy W

2015-08-01

The Schiff bases of chitosan were synthesized by the reaction of chitosan with 3-(4-substituted-phenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde. The structure of the prepared chitosan derivatives was characterized by FT-IR spectroscopy, elemental analysis, and X-ray diffraction studies and thermogravimetric analysis (TG). The results show that the specific properties of Schiff bases of chitosan can be altered by modifying the molecular structures with proper substituent groups.TG results reveal that the thermal stability of the prepared chitosan Schiff bases was lower than chitosan. The activation energy of decomposition was calculated using Coats-Redfern model. The antimicrobial activity of chitosan and Schiff bases of chitosan were investigated against Streptococcus pneumonia, Bacillis subtilis, Escherichia coli (as examples of bacteria) and Aspergillus fumigatus, Geotricum candidum and Syncephalastrum recemosum (as examples of fungi). The results indicated that the antimicrobial activity of the Schiff bases was stronger than that of chitosan and was dependent on the substituent group. The activity of un-substituted arylpyrazole chitosan derivative toward the investigated bacteria and fungi species was better than the other derivatives. Copyright © 2015 Elsevier B.V. All rights reserved.

Ethanolic extract of propolis for biodegradable films packaging enhanced with chitosan

NASA Astrophysics Data System (ADS)

Ismail, M. I.; Roslan, A.; Saari, N. S.; Hashim, K. H.; Kalamullah, M. R.

2017-09-01

The use of industrial organic waste which are chitosan and propolis as materials for the development of biodegradable and active packaging is economical and environmentally appealing. Processing of propolis-chitosan film can minimize waste, and produce low-cost added value biopolymer packaging films for targeted applications. This aims of this research is to develop and characterize a biodegradable films by incorporating chitosan with propolis extract to enhance the functional properties for potential use as active food packaging. The film's moisture content, solubility and antimicrobial activity increase due to increasing volume of propolis extract which are 0 ml, 1.2 ml and 2.4 ml of propolis extract. Propolis-chitosan film with 2.4 ml of propolis extract is more soluble in water compared to propolis-chitosan film with 0 ml of propolis extract and 1.2 ml of propolis extract. The higher the volume of the propolis extract used, the higher the solubility of film in the water. The moisture content also will increase when higher volume of propolis extract used. Characterization of moisture content, solubility and antimicrobial activities revealed the benefits of adding propolis extract into chitosan films and the potential of using the developed film as active food packaging.

Chemical composition and biological activity of essential oils from wild growing aromatic plant species of Skimmia laureola and Juniperus macropoda from Western Himalaya

USDA-ARS?s Scientific Manuscript database

The Himalayan region is very rich in a great variety of medicinal plants. In this investigation the essential oils of two selected species are described for their antimicrobial and larvicidal as well as biting deterrent activities. Additionally, the odors are characterized. Analyzed by simultaneous ...

Antimicrobial activity predictors benchmarking analysis using shuffled and designed synthetic peptides.

PubMed

Porto, William F; Pires, Állan S; Franco, Octavio L

2017-08-07

The antimicrobial activity prediction tools aim to help the novel antimicrobial peptides (AMP) sequences discovery, utilizing machine learning methods. Such approaches have gained increasing importance in the generation of novel synthetic peptides by means of rational design techniques. This study focused on predictive ability of such approaches to determine the antimicrobial sequence activities, which were previously characterized at the protein level by in vitro studies. Using four web servers and one standalone software, we evaluated 78 sequences generated by the so-called linguistic model, being 40 designed and 38 shuffled sequences, with ∼60 and ∼25% of identity to AMPs, respectively. The ab initio molecular modelling of such sequences indicated that the structure does not affect the predictions, as both sets present similar structures. Overall, the systems failed on predicting shuffled versions of designed peptides, as they are identical in AMPs composition, which implies in accuracies below 30%. The prediction accuracy is negatively affected by the low specificity of all systems here evaluated, as they, on the other hand, reached 100% of sensitivity. Our results suggest that complementary approaches with high specificity, not necessarily high accuracy, should be developed to be used together with the current systems, overcoming their limitations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Composition and antimicrobial activity of the essential oils of Laserpitium latifolium L. and L. ochridanum Micevski (Apiaceae).

PubMed

Popović, Višnja B; Petrović, Silvana D; Milenković, Marina T; Drobac, Milica M; Couladis, Maria A; Niketić, Marjan S

2015-01-01

The chemical composition and antimicrobial activity of essential oils of Laserpitium latifolium and L. ochridanum were investigated. The essential oils were isolated by steam distillation and characterized by GC-FID and GC/MS analyses. All essential oils were distinguished by high contents of monoterpenes, and α-pinene was the most abundant compound in the essential oils of L. latifolium underground parts and fruits (contents of 44.4 and 44.0%, resp.). The fruit essential oil was also rich in sabinene (26.8%). Regarding the L. ochridanum essential oils, the main constituents were limonene in the fruit oil (57.7%) and sabinene in the herb oil (25.9%). The antimicrobial activity of these essential oils as well as that of L. ochridanum underground parts, whose composition was reported previously, was tested by the broth-microdilution method against four Gram-positive and three Gram-negative bacteria and two Candida albicans strains. Except the L. latifolium underground-parts essential oil, the other investigated oils showed a high antimicrobial potential against Staphylococcus aureus, S. epidermidis, Micrococcus luteus, or Candida albicans (minimal inhibitory concentrations of 13.0-73.0 μg/ml), comparable to or even higher than that of thymol, which was used as reference compound. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

Antibacterial activity and composition of essential oils from Pelargonium graveolens L'Her and Vitex agnus-castus L

PubMed Central

Ghannadi, A; Bagherinejad, MR; Abedi, D; Jalali, M; Absalan, B; Sadeghi, N

2012-01-01

Background and Objectives Essential oils are volatile compounds that have been used since Middle Ages as antimicrobial, anti-inflammatory, sedative, local anesthetic and food flavoring agents. In the current study, essential oils of Pelargonium graveolens L'Her and Vitex agnus-castus L. were analyzed for their antibacterial activities. Materials and Methods The chemical compositions of essential oils were characterized by GC-MS. Disc diffusion method was used to study antimicrobial activity. Results and Conclusion Inhibition zones showed that the essential oils of the two plants were active against all of the studied bacteria (except Listeria monocytogenes). The susceptibility of the strains changed with the dilution of essential oils in DMSO. The pure essential oils showed the most extensive inhibition zones and they were very effective antimicrobial compounds compared to chloramphenicol and amoxicillin. The most susceptible strain against these two essential oils was Staphylococcus aureus. It seems that β-citronellol is a prominent part of P. graveolens volatile oil and caryophyllene oxide is a famous and important part of V. agnus-castus volatile oil and their probable synergistic effect with other constituents are responsible for the antibacterial effects of these oils. However further studies must be performed to confirm the safety of these oils for use as antimicrobial agents and natural preservatives in different products. PMID:23205247

Synthesis, spectroscopic characterization, antimicrobial evaluation and molecular docking study of novel triazine-quinazolinone based hybrids

NASA Astrophysics Data System (ADS)

Dinari, Mohammad; Gharahi, Fateme; Asadi, Parvin

2018-03-01

A new series of 1,3,5-triazine incorporating aromatic quinazolinone moieties as a potential antimicrobial agents is reported. The first chlorine group of the cyanuric chloride (1) was replaced by aniline and the second one was replaced by various aromatic amines. The prepared monochlorotriazine was allowed to react with hydrazine and subsequently it was reacted with 2-methyl-4H-benzo[1,3]oxazin-4-one to obtain novel triazine-quinazolinone based hybrids (9a-f). The chemical structure and purity of the hybrid compounds were evaluated by different techniques such as thin layer chromatography, melting point, Fourier-transform infrared (FTIR), 1H and 13C NMR spectra and elemental analysis. Antimicrobial activity of the hybrid compounds were study by three Gram-negative bacteria (Salmonella entritidis, Escherichia coli, Pseudomonas aeruginosa) and three Gram-positive bacteria (Staphylococcus aureus, Listeria monocitogenes, Bacillus subtilis) as well as Candida albicansas a yeast-like fungus using the serial broth dilution method. Among them, compound 9d with benzenesulfonamide group showed higher antimicrobial activity with a minimum inhibitory concentration (MIC) value of 16 μg/mL. Furthermore, compounds 5d, 9a and 9b showed good activity against several tested strains. In addition, docking simulation was perform to position best antibacterial compounds in to the S. aureus dihydrofolate reductase (DHFR) active site to determine the probable binding conformations.

Ionic liquids-water interfacial preparation of triangular Ag nanoplates and their shape-dependent antibacterial activity.

PubMed

Lu, Weiwei; Yao, Kaisheng; Wang, Jianji; Yuan, Jiongliang

2015-01-01

As a class of green and designable solvents, ionic liquids (ILs) have been used extensively in inorganic synthesis. In those schemes, ILs were usually used as reaction media to replace water and organic solvents, and/or used as stabilizer and capping agents to act like an amphiphilic molecule or polymer. However, the unique properties of ILs were not fully utilized in the area of material preparation. In this study, a new protocol of "ILs-water interfacial synthesis" was developed and used for the preparation of Ag nanomaterials. Taking the advantage of tunable property of ILs-water interface, Ag nanomaterials with different morphology such as triangular nanoplates, polygonal nanoplates, and nanoparticles could be facilely obtained. Growth mechanism of the triangular Ag nanoplates has been investigated from structural characterization and molecular dynamics (MD) simulation. It was shown that growth of the nanoplates was under kinetic control mainly due to high viscosity and ionicity of the ILs. Furthermore, the antimicrobial performance of these Ag samples was tested to study the influence of shape of the Ag nanomaterials on the antimicrobial activity and the related antimicrobial mechanism. The results suggested that the efficient antimicrobial activity of the triangular Ag nanoplates was ascribed to their sharp corners and edges and large areas of active (111) crystal plane, which leads to the higher amount of leaching Ag(+) ion. Copyright © 2014 Elsevier Inc. All rights reserved.

Antiandrogen and Antimicrobial Aspects of Coordination Compounds of Palladium(II), Platinum(II) and Lead(II)

PubMed Central

Joshi, S. C.; Kulshrestha, Shalini; Nagpal, Pooja; Bansal, Anil

2001-01-01

Synthesis, characterization and antimicrobial activities of an interesting class of biologically potent macrocyclic complexes have been carried out. All the complexes have been evaluated for their antimicrobial effects on different species of pathogenic fungi and bacteria. The testicular sperm density, testicular sperm morphology, sperm motility, density of cauda epididymal spermatozoa and fertility in mating trails and biochemical parameters of reproductive organs have been examined and discussed. The resulting biologically active [M(MaLn)(R2)]Cl2 and [Pb(MaLn)(R2)X2] (where, M = PdII or PtII and X = Cl or NO3) type of complexes have been synthesized by the reactions of macrocyclic ligands (MaLn) with metal salts and different diamines in 1:1:1 molar ratio in methanol. Initially the complexes were characterized by elemental analyses, molecular weight determinations and conductivity measurements. The mode of bonding was established on the basis of IR, 1H NMR, 13C NMR, 195Pt NMR, 207Pb NMR, XRD and electronic spectral studies. The macrocyclic ligand coordinates through the four azomethine nitrogen atoms which are bridged by benzil moieties. IR spectra suggest that the pyridine nitrogen is not coordinating. The palladium and platinum complexes exhibit tetracoordinated square-planar geometry, whereas a hexacoordinated octahedral geometry is suggested for lead complexes. PMID:18475989

Synthesis and spectral characterization of Zn(II) microsphere series for antimicrobial application

NASA Astrophysics Data System (ADS)

Singh, Ajay K.; Pandey, Sarvesh K.; Pandey, O. P.; Sengupta, S. K.

2014-09-01

Microsphere series have been synthesized by reacting zinc(II) acetate dihydrate with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole/oxadiazole/triazole with salicylaldehyde. Elemental analysis suggests that the complexes have 1:2 and 1:1 stoichiometry of the type [Zn(L)2(H2O)2] and [Zn(L‧)(H2O)2]; LH = Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thia/oxadiazole with salicylaldehyde; L‧H2 = Schiff bases derived from 3-(substituted phenyl)-4-amino-5-hydrazino-1,2,4-triazole and salicylaldehyde and were characterized by elemental analyses, IR, 1H NMR and 13C NMR spectral data. Scanning electron microscopy (SEM) showed that synthesized materials have microsphere like structure and there EDX analysis comparably matches with elemental analysis. For the antimicrobial application Schiff bases and their zinc(II) complexes were screened for four bacteria e.g. Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Streptococcus pyogenes and four fungi e.g. Cyrtomium falcatum, Aspergillus niger, Fusarium oxysporium and Curvularia pallescence by the reported method. Schiff base and Zn(II) compounds showed significant antimicrobial activities. However, activities increase upon chelation. Thermal analysis (TGA) data of compound (10) showed its stability up to 300 °C.

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

PubMed

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.

Phylogenetic study of sponge associated bacteria from the Lakshadweep archipelago and the antimicrobial activities of their secondary metabolites.

PubMed

Gopi, M; Ajith Kumar, T T; Balagurunathan, R; Vinoth, R; Dhaneesh, K V; Rajasekaran, R; Balasubramanian, T

2012-02-01

Marine ecosystem of the Lakshadweep archipelago is unique and known to have a very high degree of biodiversity with a number of endemic flora and fauna. The present study focuses to isolate the endosymbiotic microorganism from sponges and its effectiveness against marine ornamental fish pathogens. The sponges were collected from Agatti island of Lakshadweep archipelago and identified as Clathria procera, Sigmadocia fibulata and Dysidea granulosa. In which, 15 different types of bacteria were isolated and screened against marine ornamental fish pathogens (A. hydrophila, Vibrio alginolyticus, V. harveyii, V. parahaemolyticus and Pseudomonas fluorescens). The strain S25 was found as potential bacteria based on their antimicrobial activity against the fish pathogens. Molecular identification of the potential strain (S25) of the 16S rRNA gene showed 99% identity with Acinetobacter sp. The sequenced 16 s rRNA gene with 1,081 bp in length was submitted in NCBI Genbank and Accession was obtained (GenBank Accession number HM004071). The strain exhibited high similarity (99%) with the 16S rRNA gene of Acinetobacter calcoaceticus from GenBank database. Crude extract obtained with acetone and ethyl acetate from extracellular products of S25 showed significant antimicrobial activity by disc diffusion assay using 1,500 μg/ml of crude extract. Extracellular metobolite of A. calcoaceticus was extracted by shake flask method and the crude extract was partially purified by thin layer chromatography. Partially purified crude extract showed significant inhibition zone of antimicrobial activity (A. hydrophila, V. alginolyticus, V. parahaemolyticus) and less similar activity against V. harveyii and P. fluorescens. This is the first report on A. calcoaceticus isolated from sponges of Lakshadweep archipelago and the studies are underway to characterize and purify the antimicrobial compounds of the potential bacteria.

Antimicrobial Activity of Extracts of the Oyster Culinary Medicinal Mushroom Pleurotus ostreatus (Higher Basidiomycetes) and Identification of a New Antimicrobial Compound.

PubMed

Younis, Ahmed M; Wu, Fang-Sheng; El Shikh, Hussien H

2015-01-01

Pleurotus ostreatus is an edible mushroom that also has high medicinal values. In this study, P. ostreatus was tested for its ability to inhibit the growth of fungi and bacteria. The freeze-dried fruiting body, broth from submerged culture, and mycelial biomass of P. ostreatus were extracted using alcohols and water as solvents. The extracts were then tested for their antimicrobial activity against the growth of fungi and bacteria. It was observed that the water extract from fruiting bodies had the strongest effect in inhibiting the growth of most fungi. The most sensitive test microfungi to the inhibition were Candida albicans, Cryptococcus humicola, and Trichosporon cutaneum, and the most sensitive test bacteria were Staphylococcus aureus followed by Escherichia coli. Water extracts from culture broth or mycelial biomass were moderately inhibitive to the growth of fungi and bacteria. The alcohol-based solvents from all samples had much less antimicrobial activity against most test microorganisms. An antimicrobial compound was purified from the water extracts of fruiting bodies with Sephadex G 100 column chromatography and characterized by infrared absorption spectrum (IR), nuclear magnetic resonance (NMR), and mass spectroscopic analysis. We have identified this compound to be 3-(2-aminopheny1thio)-3-hydroxypropanoic acid. This purified compound had a minimum inhibitory concentration of 30 µg/mL and 20 µg/mL against the growth of fungi and bacteria, respectively.

Crisamicin A, a new antibiotic from Micromonospora. I. Taxonomy of the producing strain, fermentation, isolation, physico-chemical characterization and antimicrobial properties.

PubMed

Nelson, R A; Pope, J A; Luedemann, G M; McDaniel, L E; Schaffner, C P

1986-03-01

A microorganism, designated as RV-79-9-101 and now identified as Micromonospora purpureochromogenes subsp. halotolerans, isolated from a mud sample in the Philippines, has been shown to produce a complex of antibiotics called crisamicins. Thin-layer chromatography and bioautography, employing solvent extracts of whole fermentation broths, revealed a minimum of five antimicrobial components. The major biologically-active component of the antibiotic complex, crisamicin A, was obtained in pure form after preparative silica gel column chromatography followed by crystallization. Based on physico-chemical data crisamicin A has been identified as a novel member of the isochromanequinone group of antibiotics. It exhibits excellent in vitro activity against Gram-positive bacteria but little or no activity towards Gram-negative bacteria or fungi.

Analytical characterization and structure elucidation of metabolites from Aspergillus ochraceus MP2 fungi.

PubMed

Meenupriya, J; Thangaraj, M

2011-10-01

To isolate and characterize the bioactive secondary metabolites from Aspergillus ochraceus (A. ochraceus) MP2 fungi. The anti bacterial activity of marine sponge derived fungi A. ochraceus MP2 was thoroughly investigated against antagonistic human pathogens. The optimum inhibitory concentration of the fungi in the elite solvent was also determined. The promising extracts that showed good antimicrobial activity were subjected to further analytical separation to get individual distinct metabolites and the eluants were further identified by GC MS instrumental analysis. The molecular characterization of the elite fungal strains were done by isolating their genomic DNA and amplify the internal transcribed spacer (ITS) region of 5.8s rRNA using specific ITS primer. The novelty of the strain was proved by homology search tools and elite sequences was submitted to GENBANK. Three bioactive compounds were characterized to reveal their identity, chemical formula and structure. The first elutant was identified asα- Campholene aldehyde with chemical formula C10 H16 O and molecular weight 152 Da. The second elutant was identified as Lucenin-2 and chemical formula C27 H30 O16 and molecular weight 610 Da. The third elutant was identified as 6-Ethyloct- 3-yl- 2- ethylhexyl ester with Chemical formula C26 H42 O4 with molecular weight 418 Da. The isolated compounds showed significant antimicrobial activity against potential human pathogens. Microbial secondary metabolites represent a large source of compounds endowed with ingenious structures and potent biological activities.

Anti-microbial Activity of Tulsi {Ocimum Sanctum (Linn.)} Extract on a Periodontal Pathogen in Human Dental Plaque: An Invitro Study

PubMed Central

Devaraj, C.G.; Agarwal, Payal

2016-01-01

Introduction Tulsi is a popular healing herb in Ayurvedic medicine. It is widely used in the treatment of several systemic diseases because of its anti-microbial property. However, studies documenting the effect of Tulsi on oral disease causing organisms are rare. Hence, an attempt was made to determine the effect of Tulsi on a periodontal microorganism in human dental plaque. Aim To determine if Ocimum sanctum (Linn.) has an anti-microbial activity (Minimum Inhibitory Concentration and zone of inhibition) against Actinobacillus actinomycetemcomitans in human dental plaque and to compare the antimicrobial activity of Ocimum sanctum(Linn.) extract with 0.2% chlorhexidine as the positive control and dimethyl sulfoxide as the negative control. Materials and Methods A lab based invitro experimental study design was adopted. Ethanolic extract of Ocimum sanctum (Linn.) was prepared by the cold extraction method. The extract was diluted with an inert solvent, dimethyl sulfoxide, to obtain ten different concentrations (1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%) of extract. Plaque sample was collected from 05 subjects diagnosed with periodontal disease. Isolation of Actinobacillus actinomycetemcomitans from plaque samples was done using Tryptic Soy Serum Bacitracin Vancomycin agar (TSBV) medium. Identification of Actinobacillus actinomycetemcomitans was done based on cultural, microscopic, biochemical characterization and multiple drug resistance patterns. Anti-microbial activity of Ocimum sanctum (Linn.) extract was tested by agar well-diffusion method against 0.2% chlorhexidine as a positive control and dimethyl sulfoxide as a negative control. The zone of inhibition was measured in millimeters using Vernier callipers. Results At the 6% w/v concentration of Ocimum sanctum (Linn.) extract, a zone of inhibition of 22 mm was obtained. This was the widest zone of inhibition observed among all the 10 different concentrations tested. The zone of inhibition for positive control was 25mm and no zone of inhibition was observed around the negative control. Conclusion Ocimum sanctum (Linn.) extract demonstrated an antimicrobial activity against Actinobacillus actinomycetemcomitans. The maximum antimicrobial potential was observed at the 6% concentration level. PMID:27135002

Anti-microbial Activity of Tulsi {Ocimum Sanctum (Linn.)} Extract on a Periodontal Pathogen in Human Dental Plaque: An Invitro Study.

PubMed

Eswar, Pranati; Devaraj, C G; Agarwal, Payal

2016-03-01

Tulsi is a popular healing herb in Ayurvedic medicine. It is widely used in the treatment of several systemic diseases because of its anti-microbial property. However, studies documenting the effect of Tulsi on oral disease causing organisms are rare. Hence, an attempt was made to determine the effect of Tulsi on a periodontal microorganism in human dental plaque. To determine if Ocimum sanctum (Linn.) has an anti-microbial activity (Minimum Inhibitory Concentration and zone of inhibition) against Actinobacillus actinomycetemcomitans in human dental plaque and to compare the antimicrobial activity of Ocimum sanctum(Linn.) extract with 0.2% chlorhexidine as the positive control and dimethyl sulfoxide as the negative control. A lab based invitro experimental study design was adopted. Ethanolic extract of Ocimum sanctum (Linn.) was prepared by the cold extraction method. The extract was diluted with an inert solvent, dimethyl sulfoxide, to obtain ten different concentrations (1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%) of extract. Plaque sample was collected from 05 subjects diagnosed with periodontal disease. Isolation of Actinobacillus actinomycetemcomitans from plaque samples was done using Tryptic Soy Serum Bacitracin Vancomycin agar (TSBV) medium. Identification of Actinobacillus actinomycetemcomitans was done based on cultural, microscopic, biochemical characterization and multiple drug resistance patterns. Anti-microbial activity of Ocimum sanctum (Linn.) extract was tested by agar well-diffusion method against 0.2% chlorhexidine as a positive control and dimethyl sulfoxide as a negative control. The zone of inhibition was measured in millimeters using Vernier callipers. At the 6% w/v concentration of Ocimum sanctum (Linn.) extract, a zone of inhibition of 22 mm was obtained. This was the widest zone of inhibition observed among all the 10 different concentrations tested. The zone of inhibition for positive control was 25mm and no zone of inhibition was observed around the negative control. Ocimum sanctum (Linn.) extract demonstrated an antimicrobial activity against Actinobacillus actinomycetemcomitans. The maximum antimicrobial potential was observed at the 6% concentration level.

Antimicrobial and immune modulatory effects of lactic acid and short chain fatty acids produced by vaginal microbiota associated with eubiosis and bacterial vaginosis

PubMed Central

Aldunate, Muriel; Srbinovski, Daniela; Hearps, Anna C.; Latham, Catherine F.; Ramsland, Paul A.; Gugasyan, Raffi; Cone, Richard A.; Tachedjian, Gilda

2015-01-01

Lactic acid and short chain fatty acids (SCFAs) produced by vaginal microbiota have reported antimicrobial and immune modulatory activities indicating their potential as biomarkers of disease and/or disease susceptibility. In asymptomatic women of reproductive-age the vaginal microbiota is comprised of lactic acid-producing bacteria that are primarily responsible for the production of lactic acid present at ~110 mM and acidifying the vaginal milieu to pH ~3.5. In contrast, bacterial vaginosis (BV), a dysbiosis of the vaginal microbiota, is characterized by decreased lactic acid-producing microbiota and increased diverse anaerobic bacteria accompanied by an elevated pH>4.5. BV is also characterized by a dramatic loss of lactic acid and greater concentrations of mixed SCFAs including acetate, propionate, butyrate, and succinate. Notably women with lactic acid-producing microbiota have more favorable reproductive and sexual health outcomes compared to women with BV. Regarding the latter, BV is associated with increased susceptibility to sexually transmitted infections (STIs) including HIV. In vitro studies demonstrate that lactic acid produced by vaginal microbiota has microbicidal and virucidal activities that may protect against STIs and endogenous opportunistic bacteria as well as immune modulatory properties that require further characterization with regard to their effects on the vaginal mucosa. In contrast, BV-associated SCFAs have far less antimicrobial activity with the potential to contribute to a pro-inflammatory vaginal environment. Here we review the composition of lactic acid and SCFAs in respective states of eubiosis (non-BV) or dysbiosis (BV), their effects on susceptibility to bacterial/viral STIs and whether they have inherent microbicidal/virucidal and immune modulatory properties. We also explore their potential as biomarkers for the presence and/or increased susceptibility to STIs. PMID:26082720

Molecular Analysis, Biochemical Characterization, Antimicrobial Activity, and Immunological Analysis of Proteus mirabilis Isolated from Broilers.

PubMed

Yeh, Hung-Yueh; Line, John E; Hinton, Arthur

2018-03-01

Proteus mirabilis, a Gram-negative bacterium, is ubiquitous in the environment and is considered as the normal microflora in the human gastrointestinal tract. However, this bacterium is an opportunistic pathogen in humans, often causing urinary tract infections. Moreover, Proteus has been frequently isolated from food animals, including poultry. Whether this bacterium contributes to the foodborne illness in humans is unclear. In this report, P. mirabilis isolates recovered from broilers during housing in the units were characterized, their antimicrobial activity was assayed, and broiler immune response to the soluble proteins was determined. Cecal contents and fecal droppings were treated according to the standard protocol for isolation. Speciation based on biochemical reactions and the antimicrobial activity of the isolates were carried out using commercial kits. Immunoblot was assayed to determine immune status of broilers against P. mirabilis. A total of 10 isolates of P. mirabilis were selected for further characterization. These isolates could grow in pH 6.0 and 1% NaCl conditions. They were resistant to sodium lactate, troleandomycin, rifamycin SV, vancomycin, but sensitive to nalidixic acid, cefotaxime and novobiocin. Moreover, the CTX, ACC, CMY-1, BIC, NDM, VEB, qnrB and qnrD genes were detected by PCR amplification in all isolates. Sera from broilers harboring this bacterium reacted to the P. mirabilis soluble proteins, but not from litter- and age-matched P. mirabilis negative and SPF chickens, indicating that this bacterium infected chickens that could have humoral immune response against P. mirabilis. This study provides a rationale for further monitoring P. mirabilis during poultry production to determine whether this bacterium poses potential threats to public health. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

The Integral Method, a new approach to quantify bactericidal activity.

PubMed

Gottardi, Waldemar; Pfleiderer, Jörg; Nagl, Markus

2015-08-01

The bactericidal activity (BA) of antimicrobial agents is generally derived from the results of killing assays. A reliable quantitative characterization and particularly a comparison of these substances, however, are impossible with this information. We here propose a new method that takes into account the course of the complete killing curve for assaying BA and that allows a clear-cut quantitative comparison of antimicrobial agents with only one number. The new Integral Method, based on the reciprocal area below the killing curve, reliably calculates an average BA [log10 CFU/min] and, by implementation of the agent's concentration C, the average specific bactericidal activity SBA=BA/C [log10 CFU/min/mM]. Based on experimental killing data, the pertaining BA and SBA values of exemplary active halogen compounds were established, allowing quantitative assertions. N-chlorotaurine (NCT), chloramine T (CAT), monochloramine (NH2Cl), and iodine (I2) showed extremely diverging SBA values of 0.0020±0.0005, 1.11±0.15, 3.49±0.22, and 291±137log10 CFU/min/mM, respectively, against Staphylococcus aureus. This immediately demonstrates an approximately 550-fold stronger activity of CAT, 1730-fold of NH2Cl, and 150,000-fold of I2 compared to NCT. The inferred quantitative assertions and conclusions prove the new method suitable for characterizing bactericidal activity. Its application comprises the effect of defined agents on various bacteria, the consequence of temperature shifts, the influence of varying drug structure, dose-effect relationships, ranking of isosteric agents, comparison of competing commercial antimicrobial formulations, and the effect of additives. Copyright © 2015 Elsevier B.V. All rights reserved.

Chitosan-Copper (II) complex as antibacterial agent: synthesis, characterization and coordinating bond- activity correlation study

NASA Astrophysics Data System (ADS)

Mekahlia, S.; Bouzid, B.

2009-11-01

The antimicrobial activity of chitosan is unstable and sensitive to many factors such as molecular weight. Recent investigations showed that low molecular weight chitosan exhibited strong bactericidal activities compared to chitosan with high molecular weight. Since chitosan degradation can be caused by the coordinating bond, we attempt to synthesize and characterize the chitosan-Cu (II) complex, and thereafter study the coordinating bond effect on its antibacterial activity against Salmonella enteritidis. Seven chitosan-copper complexes with different copper contents were prepared and characterized by FT-IR, UV-vis, XRD and atomic absorption spectrophotometry (AAS). Results indicated that for chitosan-Cu (II) complexes with molar ratio close to 1:1, the inhibition rate reached 100%.

Identification and characterization of antimicrobial peptides from the skin of the endangered frog Odorrana ishikawae.

PubMed

Iwakoshi-Ukena, Eiko; Ukena, Kazuyoshi; Okimoto, Aiko; Soga, Miyuki; Okada, Genya; Sano, Naomi; Fujii, Tamotsu; Sugawara, Yoshiaki; Sumida, Masayuki

2011-04-01

The endangered anuran species, Odorrana ishikawae, is endemic to only two small Japanese Islands, Amami and Okinawa. To assess the innate immune system in this frog, we investigated antimicrobial peptides in the skin using artificially bred animals. Nine novel antimicrobial peptides containing the C-terminal cyclic heptapeptide domain were isolated on the basis of antimicrobial activity against Escherichia coli. The peptides were members of the esculentin-1 (two peptides), esculentin-2 (one peptide), palustrin-2 (one peptide), brevinin-2 (three peptides) and nigrocin-2 (two peptides) antimicrobial peptide families. They were named esculentin-1ISa, esculentin-1ISb, esculentin-2ISa, palustrin-2ISa, brevinin-2ISa, brevinin-2ISb, brevinin-2ISc, nigrocin-2ISa and nigrocin-2ISb. Peptide primary structures suggest a close relationship with the Asian odorous frogs, Odorrana grahami and Odorrana hosii. These antimicrobial peptides possessed a broad-spectrum of growth inhibition against five microorganisms (E. coli, Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis and Candida albicans). Nine different cDNAs encoding the precursor proteins were also cloned and showed that the precursor proteins exhibited a signal peptide, an N-terminal acidic spacer domain, a Lys-Arg processing site and an antimicrobial peptide at the C-terminus. Copyright © 2010 Elsevier Inc. All rights reserved.

Biosynthesis and Characterization of AgNPs–Silk/PVA Film for Potential Packaging Application

PubMed Central

Tao, Gang; Cai, Rui; Wang, Yejing; Song, Kai; Guo, Pengchao; Zhao, Ping; Zuo, Hua; He, Huawei

2017-01-01

Bionanocomposite packaging materials have a bright future for a broad range of applications in the food and biomedical industries. Antimicrobial packaging is one of the bionanocomposite packaging materials. Silver nanoparticle (AgNP) is one of the most attractive antimicrobial agents for its broad spectrum of antimicrobial activity against microorganisms. However, the traditional method of preparing AgNPs-functionalized packaging material is cumbersome and not environmentally friendly. To develop an efficient and convenient biosynthesis method to prepare AgNPs-modified bionanocomposite material for packaging applications, we synthesized AgNPs in situ in a silk fibroin solution via the reduction of Ag+ by the tyrosine residue of fibroin, and then prepared AgNPs–silk/poly(vinyl alcohol) (PVA) composite film by blending with PVA. AgNPs were synthesized evenly on the surface or embedded in the interior of silk/PVA film. The prepared AgNPs–silk/PVA film exhibited excellent mechanical performance and stability, as well as good antibacterial activity against both Gram-negative and Gram-positive bacteria. AgNPs–silk/PVA film offers more choices to be potentially applied in the active packaging field. PMID:28773026

Biosynthesis and Characterization of AgNPs-Silk/PVA Film for Potential Packaging Application.

PubMed

Tao, Gang; Cai, Rui; Wang, Yejing; Song, Kai; Guo, Pengchao; Zhao, Ping; Zuo, Hua; He, Huawei

2017-06-17

Bionanocomposite packaging materials have a bright future for a broad range of applications in the food and biomedical industries. Antimicrobial packaging is one of the bionanocomposite packaging materials. Silver nanoparticle (AgNP) is one of the most attractive antimicrobial agents for its broad spectrum of antimicrobial activity against microorganisms. However, the traditional method of preparing AgNPs-functionalized packaging material is cumbersome and not environmentally friendly. To develop an efficient and convenient biosynthesis method to prepare AgNPs-modified bionanocomposite material for packaging applications, we synthesized AgNPs in situ in a silk fibroin solution via the reduction of Ag⁺ by the tyrosine residue of fibroin, and then prepared AgNPs-silk/poly(vinyl alcohol) (PVA) composite film by blending with PVA. AgNPs were synthesized evenly on the surface or embedded in the interior of silk/PVA film. The prepared AgNPs-silk/PVA film exhibited excellent mechanical performance and stability, as well as good antibacterial activity against both Gram-negative and Gram-positive bacteria. AgNPs-silk/PVA film offers more choices to be potentially applied in the active packaging field.

Synthesis of poly acrylic acid modified silver nanoparticles and their antimicrobial activities.

PubMed

Ni, Zhihui; Wang, Zhihua; Sun, Lei; Li, Binjie; Zhao, Yanbao

2014-08-01

Poly acrylic acid modified silver (Ag/PAA) nanoparticles (NPs) have been successfully synthesized in the aqueous solution by using tannic acid as a reductant. The structure, morphology and composition of Ag/PAA NPs were characterized by various techniques such as X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible absorption spectroscopy (UV-vis) and thermogravimetry analysis (TGA). The results show that PAA/Ag NPs have a quasi-ball shape with an average diameter of 10 nm and exhibit well crystalline, and the reaction conditions have some effect on products morphology and size distribution. In addition, the as-synthesized Ag/PAA NPs antimicrobial activities against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) were evaluated by the methods of broth dilution, cup diffusion, optical density (OD600) and electron microscopy observation. The as-synthesized Ag/PAA NPs exhibit excellent antibacterial activity. The antimicrobial mechanism may be attributed to the damaging of bacterial cell membrane and causing leakage of cytoplasm. Copyright © 2014 Elsevier B.V. All rights reserved.

Antimicrobial activity of immobilized lactoferrin and lactoferricin.

PubMed

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

2017-11-01

Lactoferrin and lactoferricin were immobilized on glass surfaces via two linkers, 4-azidobenzoic acid (ABA) or 4-fluoro-3-nitrophenyl azide (FNA). The resulting surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The antimicrobial activity of the surfaces was determined using Pseudomonas aeruginosa and Staphylococcus aureus strains by fluorescence microscopy. Lactoferrin and lactoferricin immobilization was confirmed by XPS showing significant increases (p < 0.05) in nitrogen on the glass surface. The immobilization of both proteins slightly increased the overall hydrophobicity of the glass. Both lactoferrin and lactoferricin immobilized on glass significantly (p < 0.05) reduced the numbers of viable bacterial cells adherent to the glass. For P. aeruginosa, the immobilized proteins consistently increased the percentage of dead cells compared to the total cells adherent to the glass surfaces (p < 0.03). Lactoferrin and lactoferricin were successfully immobilized on glass surfaces and showed promising antimicrobial activity against pathogenic bacteria. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2612-2617, 2017. © 2016 Wiley Periodicals, Inc.

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

PubMed Central

Malik, Erum; Dennison, Sarah R.; Harris, Frederick; Phoenix, David A.

2016-01-01

Antimicrobial peptides (AMPs) are potent antibiotics of the innate immune system that have been extensively investigated as a potential solution to the global problem of infectious diseases caused by pathogenic microbes. A group of AMPs that are increasingly being reported are those that utilise pH dependent antimicrobial mechanisms, and here we review research into this area. This review shows that these antimicrobial molecules are produced by a diverse spectrum of creatures, including vertebrates and invertebrates, and are primarily cationic, although a number of anionic examples are known. Some of these molecules exhibit high pH optima for their antimicrobial activity but in most cases, these AMPs show activity against microbes that present low pH optima, which reflects the acidic pH generally found at their sites of action, particularly the skin. The modes of action used by these molecules are based on a number of major structure/function relationships, which include metal ion binding, changes to net charge and conformational plasticity, and primarily involve the protonation of histidine, aspartic acid and glutamic acid residues at low pH. The pH dependent activity of pore forming antimicrobial proteins involves mechanisms that generally differ fundamentally to those used by pH dependent AMPs, which can be described by the carpet, toroidal pore and barrel-stave pore models of membrane interaction. A number of pH dependent AMPs and antimicrobial proteins have been developed for medical purposes and have successfully completed clinical trials, including kappacins, LL-37, histatins and lactoferrin, along with a number of their derivatives. Major examples of the therapeutic application of these antimicrobial molecules include wound healing as well as the treatment of multiple cancers and infections due to viruses, bacteria and fungi. In general, these applications involve topical administration, such as the use of mouth washes, cream formulations and hydrogel delivery systems. Nonetheless, many pH dependent AMPs and antimicrobial proteins have yet to be fully characterized and these molecules, as a whole, represent an untapped source of novel biologically active agents that could aid fulfillment of the urgent need for alternatives to conventional antibiotics, helping to avert a return to the pre-antibiotic era. PMID:27809281

Green synthesis, antimicrobial and cytotoxic effects of silver nanoparticles using Eucalyptus chapmaniana leaves extract

PubMed Central

Sulaiman, Ghassan Mohammad; Mohammed, Wasnaa Hatif; Marzoog, Thorria Radam; Al-Amiery, Ahmed Abdul Amir; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

2013-01-01

Objective To synthesize silver nanopaticles from leaves extract of Eucalyptus chapmaniana (E. chapmaniana) and test the antimicrobial of the nanoparticles against different pathogenic bacteria, yeast and its toxicity against human acute promyelocytic leukemia (HL-60) cell line. Methods Ten milliliter of leaves extract was mixed with 90 mL of 0.01 mmol/mL or 0.02 mmol/mL aqueous AgNO3 and exposed to sun light for 1 h. A change from yellowish to reddish brown color was observed. Characterization using UV-vis spectrophotometery and X-ray diffraction analysis were performed. Antimicrobial activity against six microorganisms was tested using well diffusion method and cytoxicity test using 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a yellow tetrazole was obtained on the human leukemia cell line (HL-60). Results UV-vis spectral analysis showed silver surface plasmon resonance band at 413 nm. X-ray diffraction showed that the particles were crystalline in nature with face centered cubic structure of the bulk silver with broad beaks at 38.50° and 44.76°. The synthesized silver nanoparticles efficiently inhibited various pathogenic organisms and reduced viability of the HL-60 cells in a dose-dependent manner. Conclusions It has been demonstrated that the extract of E. chapmaniana leaves are capable of producing silver nanoparticles extracellularly and the Ag nanoparticles are quite stable in solution. Further studies are needed to fully characterize the toxicity and the mechanisms involved with the antimicrobial and anticancer activity of these particles. PMID:23570018

Synthesis, Spectral Characterization, In-vitro Antibacterial and Antifungal Activities of Novel (2e)-Ethyl-2-(2-(2, 4-Dinitrophenyl) Hydrazono)-4-(Naphthalen-2-yl)-6-Arylcyclohex-3-Enecarboxylates

PubMed Central

Kanagarajan, V; Thanusu, J; Gopalakrishnan, M

2011-01-01

In a search for new leads towards potent antimicrobial agents, an array of novel (2E)-ethyl-2-(2-(2,4-dinitrophenyl)hydrazono)-4-(naphthalen-2-yl)-6-arylcyclohex-3-ene carboxylates 17-24 were synthesized and characterized through their melting point, elemental analysis, MS, FT-IR, one-dimensional NMR (1H, D2O exchanged 1H and 13C), two dimensional HOMOCOR and HSQC spectroscopic data. In-vitro microbiological evaluations were carried out for all the newly synthesized compounds 17-24 against clinically isolated bacterial strains namely Salmonella typhii, Klebsiellapneumoniae, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, β-Hemolytic streptococcus and Micrococcus luteusand also fungal strains namely Aspergillusflavus, Aspergillusniger, Mucor, Rhizopus and Microsporumgypseumand finally, the results of their structure activity relationship were discussed. The obtained results can be used as the key step for the building of novel chemical compounds with interesting antimicrobial profiles comparable to that of the standard drugs. PMID:24250406

Synthesis, Spectral Characterization, In-vitro Antibacterial and Antifungal Activities of Novel (2e)-Ethyl-2-(2-(2, 4-Dinitrophenyl) Hydrazono)-4-(Naphthalen-2-yl)-6-Arylcyclohex-3-Enecarboxylates.

PubMed

Kanagarajan, V; Thanusu, J; Gopalakrishnan, M

2011-01-01

In a search for new leads towards potent antimicrobial agents, an array of novel (2E)-ethyl-2-(2-(2,4-dinitrophenyl)hydrazono)-4-(naphthalen-2-yl)-6-arylcyclohex-3-ene carboxylates 17-24 were synthesized and characterized through their melting point, elemental analysis, MS, FT-IR, one-dimensional NMR ((1)H, D2O exchanged (1)H and (13)C), two dimensional HOMOCOR and HSQC spectroscopic data. In-vitro microbiological evaluations were carried out for all the newly synthesized compounds 17-24 against clinically isolated bacterial strains namely Salmonella typhii, Klebsiellapneumoniae, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, β-Hemolytic streptococcus and Micrococcus luteusand also fungal strains namely Aspergillusflavus, Aspergillusniger, Mucor, Rhizopus and Microsporumgypseumand finally, the results of their structure activity relationship were discussed. The obtained results can be used as the key step for the building of novel chemical compounds with interesting antimicrobial profiles comparable to that of the standard drugs.

Synthesis, characterization, antimicrobial and antitumor reactivity of new palladium(II) complexes with methionine and tryptophane coumarine derivatives

NASA Astrophysics Data System (ADS)

Stojković, Danijela Lj; Jevtić, Verica V.; Vuković, Nenad; Vukić, Milena; Čanović, Petar; Zarić, Milan M.; Mišić, Milena M.; Radovanović, Dragče M.; Baskić, Dejan; Trifunović, Srećko R.

2018-04-01

In reaction of 3-acetyl-4-hydroxy coumarine with methionine methyl ester hydrochloride and tryptophane methyl ester hydrochloride the corresponding enamine ligands were obtained. Palladium (II) complexes were prepared in reaction of potassium-tetrachloridopalladate (II) and corresponding enamine. All compounds were characterized by microanalysis, infrared, 1H and 13C NMR spectroscopy. In vitro antitumor activity of the mentioned ligands and corresponding palladium (II) complexes, as well as me-Gly and me-Val ligands and [Pd (me-Gly)]Cl and [Pd (me-Val)2] complexes was determined by MTT assay against two leukemia cell lines (JVM-13 and MOLT-4) and against primary leukemic cells isolated from chronic lymphocytic leukemia (CLL) patients. Antimicrobial activity of the tested compound was evaluated by determining the minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) against three reference bacterial strains: E. faecalis, P. aeruginosa, S. aureus and one clinical isolate of yeast: Candida spp.

Preparation, Characterization, and In Vitro Testing of Nanoclay Antimicrobial Activities and Elicitor Capacity.

PubMed

Merino, Danila; Mansilla, Andrea Y; Casalongué, Claudia A; Alvarez, Vera A

2018-03-28

Clay-based nanocomposites (nanoclays) are interesting systems to hold a wide type of active substances with a wide field of industrial applications. Bentonite-chitosan nanoclay was obtained via cationic exchange of natural bentonite (Bent) with an aqueous solution of chitosan (CS). Their physicochemical and morphological properties were discussed under the light of Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. Bent-CS characterization indicated that CS was intercalated in 10% (w/w). This polycationic polymer was oriented mostly in a monolayer arrangement, interacting by electrostatic forces between Bent sheets. The antimicrobial action of Bent-CS nanoclay was assayed onto phytopathogens, the bacterium model Pseudomonas syringe pv. tomato DC3000 ( Psy) and the necrotrophic fungus Fusarium solani f. sp. eumartii ( F. eumartii). In addition to demonstrating cell death on both microorganisms, Bent-CS exerted elicitor property on tomato plantlets. The biological actions of this natural nanomaterial might make it proper to be used in crops.

Extraction and characterization of proteins from banana (Musa Sapientum L) flower and evaluation of antimicrobial activities.

PubMed

Sitthiya, Kewalee; Devkota, Lavaraj; Sadiq, Muhammad Bilal; Anal, Anil Kumar

2018-02-01

Ultrasonic assisted alkaline extraction of protein from banana flower was optimized using response surface methodology. The extracted proteins were characterized by Fourier transform infrared spectroscopy and molecular weight distribution was determined by gel electrophoresis. The maximum protein yield of 252.25 mg/g was obtained under optimized extraction conditions: temperature 50 °C, 30 min extraction time and 1 M NaOH concentration. The alkaline extraction produced a significantly high protein yield compared to enzymatic extraction of banana flower. Chemical finger printing of proteins showed the presence of tyrosine, tryptophan and amide bonds in extracted protein. Alkaline and pepsin assisted extracted banana flower proteins showed characteristic bands at 40 and 10 kDA, respectively. The extracted proteins showed antibacterial effects against both gram positive and gram negative bacteria. The high protein content and antimicrobial activity indicate the potential applications of banana flower in the food and feed industry.

Synthesis, characterization and antimicrobial activity of dextran stabilized silver nanoparticles in aqueous medium.

PubMed

Bankura, K P; Maity, D; Mollick, M M R; Mondal, D; Bhowmick, B; Bain, M K; Chakraborty, A; Sarkar, J; Acharya, K; Chattopadhyay, D

2012-08-01

A simple one-step rapid synthetic route is described for the preparation of silver nanoparticles by reduction of silver nitrate (AgNO3) using aqueous dextran solution which acts as both reducing and capping agent. The formation of silver nanoparticles is assured by characterization with UV-vis spectroscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The absorbance of the silver nanoparticles is observed at 423 nm. The AFM image clearly shows the surface morphology of the well-dispersed silver nanoparticles with size range of 10-60 nm. TEM images show that the nanoparticles are spherical in shape with ∼5-10 nm dimensions. The crystallinity of Ag nanoparticles is assured by XRD analysis. The antimicrobial activity of as synthesized silver nanoparticles is tested against the bacteria, Bacillus subtilis, Bacillus cereus, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The bacterial growth is inhibited by gradual reduction of the concentration of the silver nanoparticles. Copyright © 2012 Elsevier Ltd. All rights reserved.

Preparation and characterization of biocompatible magnetic carbon nanotubes

NASA Astrophysics Data System (ADS)

Shan, Yan; Chen, Kezheng; Yu, Xuegang; Gao, Lian

2010-11-01

Magnetic carbon nanotubes consisting of multi-wall carbon nanotubes (MWNTs) core and Fe3O4 shell were successfully prepared by in situ thermal decomposition of Fe(acac)3 or FeCl3 or Fe(CO)5 in 2-pyrrolidone containing acid treated MWNTs at 240 °C with the protection of nitrogen gas. The samples were characterized by TEM, XRD, SEAD, XPS and superconducting quantum interference device. Also, their biocompatibility was compared with naked carbon nanotubes. The results showed that after coated with Fe3O4 nanoparticles, the obtained magnetic carbon nanotubes show superparamagnetic characteristic at room temperature, and their blocking temperature is about 80 K. The magnetic properties of the nanotubes are relevant to the content of magnetic particles, increasing content of magnetic nanoparticles leads to higher blocking temperature and saturation magnetization. The results of antimicrobial activities to bacterial cells (Escherichia coli) showed that the MWNTs have antimicrobial activity, while the magnetic nanotubes are biocompatible even with a higher concentration than that of MWNTs.

Ribonuclease 7, an antimicrobial peptide upregulated during infection, contributes to microbial defense of the human urinary tract.

PubMed

Spencer, John David; Schwaderer, Andrew L; Wang, Huanyu; Bartz, Julianne; Kline, Jennifer; Eichler, Tad; DeSouza, Kristin R; Sims-Lucas, Sunder; Baker, Peter; Hains, David S

2013-04-01

The mechanisms that maintain sterility in the urinary tract are incompletely understood; however, recent studies stress the importance of antimicrobial peptides in protecting the urinary tract from infection. Ribonuclease 7 (RNase 7), a potent antimicrobial peptide contributing to urinary tract sterility, is expressed by intercalated cells in the renal collecting tubules and is present in the urine at levels sufficient to kill bacteria at baseline. Here, we characterize the expression and function of RNase 7 in the human urinary tract during infection. Both quantitative real-time PCR and enzyme-linked immunosorbant assays demonstrated increases in RNASE7 expression in the kidney along with kidney and urinary RNase 7 peptide concentrations with infection. While immunostaining localized RNase 7 production to the intercalated cells of the collecting tubule during sterility, its expression during pyelonephritis was found to increase throughout the nephron but not in glomeruli or the interstitium. Recombinant RNase 7 exhibited antimicrobial activity against uropathogens at low micromolar concentrations by disrupting the microbial membrane as determined by atomic force microscopy. Thus, RNase 7 expression is increased in the urinary tract with infection and has antibacterial activity against uropathogens at micromolar concentrations.

Ribonuclease 7, an antimicrobial peptide up-regulated during infection, contributes to microbial defense of the human urinary tract

PubMed Central

Spencer, John David; Schwaderer, Andrew L.; Wang, Huanyu; Bartz, Julianne; Kline, Jennifer; Eichler, Tad; DeSouza, Kristin R.; Sims-Lucas, Sunder; Baker, Peter; Hains, David S.

2012-01-01

The mechanisms that maintain sterility in the urinary tract are incompletely understood; however, recent studies stress the importance of antimicrobial peptides in protecting the urinary tract from infection. Ribonuclease 7 (RNase 7), a potent antimicrobial peptide contributing to urinary tract sterility, is expressed by intercalated cells in the renal collecting tubules and is present in the urine at levels sufficient to kill bacteria at baseline. Here, we characterize the expression and function of RNase 7 in the human urinary tract during infection. Both quantitative real-time PCR and ELISA assays demonstrated increases in RNASE7 expression in the kidney along with kidney and urinary RNase 7 peptide concentrations with infection. While immunostaining localized RNase 7 production to the intercalated cells of the collecting tubule during sterility, its expression during pyelonephritis was found to increase throughout the nephron but not in glomeruli or the interstitium. Recombinant RNase 7 exhibited antimicrobial activity against uropathogens at low micromolar concentrations by disrupting the microbial membrane as determined by atomic force microscopy. Thus, RNase 7 expression is increased in the urinary tract with infection, and has antibacterial activity against uropathogens at micromolar concentrations. PMID:23302724

Microalgae associated Brevundimonas sp. MSK 4 as the nano particle synthesizing unit to produce antimicrobial silver nanoparticles

NASA Astrophysics Data System (ADS)

Rajamanickam, Karthic; Sudha, S. S.; Francis, Mebin; Sowmya, T.; Rengaramanujam, J.; Sivalingam, Periyasamy; Prabakar, Kandasamy

2013-09-01

The biosynthesis of silver nanoparticles and its antimicrobial property was studied using bacteria isolated from Spirulina products. Isolated bacteria were identified as Bacillus sp. MSK 1 (JX495945), Staphylococcus sp. MSK 2 (JX495946), Bacillus sp. MSK 3 (JX495947) and Brevundimonas sp. MSK 4 (JX495948). Silver nanoparticles (AgNPs) were synthesized using bacterial culture filtrate with AgNO3. The initial syntheses of Ag nanoparticles were characterized by UV-vis spectrophotometer (by measuring the color change to intense brown). Fourier Transform Infrared Spectroscopy (FTIR) study showed evidence that proteins are possible reducing agents and Energy-dispersive X-ray (EDX) study showing the metal silver as major signal. The structure of AgNPs was determined by Scanning electron microscopy (SEM) and X-ray diffraction (XRD). Synthesized Ag nanoparticles with an average size of 40-65 nm have antimicrobial property against human pathogens like Proteus vulgaris, Salmonella typhi, Vibrio cholera, Streptococcus sp., Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. Among the isolates Brevundimonas sp. MSK 4 alone showed good activity in both synthesis of AgNPs and antimicrobial activity. This work demonstrates the possible use of biological synthesized silver nanoparticles to combat the drug resistant problem.

Tailoring shape and size of biogenic silver nanoparticles to enhance antimicrobial efficacy against MDR bacteria.

PubMed

Kumari, Madhuree; Pandey, Shipra; Giri, Ved Prakash; Bhattacharya, Arpita; Shukla, Richa; Mishra, Aradhana; Nautiyal, C S

2017-04-01

Spherical, rectangular, penta, and hexagonal silver nanoparticles of different dimensions were biosynthesized in an eco-friendly manner by biocontrol agent, Trichoderma viride by manipulating physical parameters, pH, temperature, and reaction time. The particles were characterized by UV-vis spectroscopy; Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM) and Fourier Transform Infra-red Spectroscopy (FTIR). Shape and size dependent antimicrobial activity of nanoparticles against human pathogens was observed. Maximum inhibition was found with spherical nanoparticles (2-5 nm) showing 40, 51, 43, 53.9 and 55.8% against Shigella sonnei, Escherichia coli, Serratia marcescens, Staphylococcus. aureus and Pseudomonas aeruginosa respectively, where as pentagonal and hexagonal nanoparticles (50-100 nm) demonstrated 32, 41, 31, 42.84 and 42.80% of inhibition as compared to control. Nanoparticles of different geometry and dimension established enhanced antagonistic activity against pathogens with all the tested antibiotics. Excellent antimicrobial efficacy was obtained with spherical nanoparticles of 2-5 nm with ampicillin and penicillin. Shape and size played major role in enhancing antimicrobial potential of silver nanoparticles, both singly and synergistically with antibiotics which can be exploited to combat the spread of multidrug resistant pathogens. Copyright © 2016. Published by Elsevier Ltd.

Novel designed VmCT1 analogs with increased antimicrobial activity.

PubMed

Pedron, Cibele Nicolaski; Torres, Marcelo Der Torossian; Lima, Julia Aparecida da Silva; Silva, Pedro Ismael; Silva, Fernanda Dias; Oliveira, Vani Xavier

2017-01-27

Antimicrobial peptides are biologically active molecules produced by a wide range of organisms as an essential component of the innate immune response. They have recently attracted great interest, since they have antimicrobial activity against a broad spectrum of microorganisms. VmCT1 is a cationic peptide from the venom of Vaejovis mexicanus smithi scorpions, which presents antibacterial activity and tends to helical structures. Its analogs were synthesized, characterized and the conformational studies were performed by circular dichroism. The peptides were designed to verify if the single and double substitutions proposed at the hydrophilic and hydrophobic portions of the amphipathic structure would alter antimicrobial activity against Gram-negative and Gram-positive bacteria, yeast and filamentous fungus, besides the hemolytic activity in human erythrocytes. Total charge of the peptides were modified from +2 to +3 by the introduction of a Lysine residue in the hydrophilic face of the amphiphilic helical structure leading to enhanced antimicrobial activity. [K] 11 -VmCT1-NH 2 presented the lower MIC value against the microorganisms (from 0.39 to 6.25 μmol L -1 ), however it showed higher hemolytic activity. The other Lysine-substituted analogs presented also lower MIC values ranging from 0.39 to 25 μmol L -1 for the microorganisms assessed. The circular dichroism spectra analyses suggest that the Lysine-substituted analogs tend to adopt helical structures in trifluoroethanol solution and vesicles (f H : 0.43-1), however they were coiled in water. Alanine substitution by a Glutamic acid residue in the hydrophilic face promotes the increase of polar angle in [E] 4 -VmCT1-NH 2 analog, which was important to led lower hemolytic activity (MHC value = 25 μmol L -1 ). [W] 9 -VmCT1-NH 2 and [E] 4 [W] 9 -VmCT1-NH 2 were designed to favors hydrophobic interactions by the introduction of Tryptophan residue. [W] 9 -VmCT1-NH 2 presented MIC values lower or similar than the model molecule in the most of microorganisms tested. These results provided information about the structure-activity relationship and showed the influence of physicochemical parameters on antimicrobial and hemolytic activity. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

New antimicrobial peptides against foodborne pathogens: From in silico design to experimental evidence.

PubMed

Palmieri, Gianna; Balestrieri, Marco; Proroga, Yolande T R; Falcigno, Lucia; Facchiano, Angelo; Riccio, Alessia; Capuano, Federico; Marrone, Raffaele; Neglia, Gianluca; Anastasio, Aniello

2016-11-15

Recently there has been growing interest in the discovery of new antimicrobial agents to increase safety and shelf-life of food products. Here, we developed an innovative approach by introducing the concept that mitochondrial targeting peptides (MTP) can interact and disrupt bacterial membranes, acting as antimicrobial agents. As proof-of-principle, we used a multidisciplinary strategy by combining in silico predictions, docking simulations and antimicrobial assays, to identify two peptides, MTP1 and MTP2, which were structurally and functionally characterized. Both compounds appeared effective against Listeria monocytogenes, one of the most important foodborne pathogens. Specifically, a significant bactericidal activity was evidenced with EC50 values of 16.8±1.2μM for MTP1 and 109±7.0μM for MTP2. Finally, NMR structure determinations suggested that MTP1 would be oriented into the membrane bilayer, while the molecular shape of MTP2 could indicate porin-mediated antimicrobial mechanisms, as predicted using molecular docking analysis. Therefore, MTPs represent alternative sources to design new potential bio-preservatives. Copyright © 2016 Elsevier Ltd. All rights reserved.

Purification, characterization, and sequencing of antimicrobial peptides, Cy-AMP1, Cy-AMP2, and Cy-AMP3, from the Cycad (Cycas revoluta) seeds.

PubMed

Yokoyama, Seiya; Kato, Kouji; Koba, Atsuko; Minami, Yuji; Watanabe, Keiichi; Yagi, Fumio

2008-12-01

Novel antimicrobial peptides (AMP), designated Cy-AMP1, Cy-AMP2, and Cy-AMP3, were purified from seeds of the cycad (Cycas revoluta) by a CM cellulofine column, ion-exchange HPLC on SP COSMOGEL, and reverse-phase HPLC. They had molecular masses of 4583.2 Da, 4568.9 Da and 9275.8 Da, respectively, by MALDI-TOF MS analysis. Half of the amino acid residues of Cy-AMP1 and Cy-AMP2 were cysteine, glycine and proline, and their sequences were similar. The sequence of Cy-AMP3 showed high homology to various lipid transfer proteins. For Cy-AMP1 and Cy-AMP2, the concentrations of peptides required for 50% inhibition (IC(50)) of the growth of plant pathogenic fungi, Gram-positive and Gram-negative bacteria were 7.0-8.9 microg/ml. The Cy-AMP3 had weak antimicrobial activity. The structural and antimicrobial characteristics of Cy-AMP1 and Cy-AMP2 indicated that they are a novel type of antimicrobial peptide belonging to a plant defensin family.

Enhanced mechanical, thermal and antimicrobial properties of poly(vinyl alcohol)/graphene oxide/starch/silver nanocomposites films.

PubMed

Usman, Adil; Hussain, Zakir; Riaz, Asim; Khan, Ahmad Nawaz

2016-11-20

In the present work, synthesis of poly(vinyl alcohol)/graphene oxide/starch/silver (PVA/GO/Starch/Ag) nanocomposites films is reported. Such films have been characterized and investigated for their mechanical, thermal and antimicrobial properties. The exfoliation of GO in the PVA matrix occurs owing to the non-covalent interactions of the polymer chains of PVA and hydrophilic surface of the GO layers. Presence of GO in PVA and PVA/starch blends were found to enhance the tensile strength of the nanocomposites system. It was found that the thermal stability of PVA as well as PVA/starch blend systems increased by the incorporation of GO where strong physical bonding between GO layers and PVA/starch blends is assumed to cause thermal barrier effects. Antimicrobial properties of the prepared films were investigated against Escherichia coli and Staphylococcus aureus. Our results show enhanced antimicrobial properties of the prepared films where PVA-GO, PVA-Ag, PVA-GO-Ag and PVA-GO-Ag-Starch showed antimicrobial activity in ascending order. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemical composition and biological activities of Salvia officinalis essential oil from Tunisia

PubMed Central

Khedher, Med Raâfet Ben; Khedher, Saoussen Ben; Chaieb, Ikbal; Tounsi, Slim; Hammami, Mohamed

2017-01-01

The aim of this study is to evaluate the chemical composition, antioxidant, antimicrobial, insecticidal and allelopathic activities of Tunisia Salvia officinalis essential oil (SoEO). The SoEO was characterized by the presence of 49 components with camphor (25.14 %), α-thujone (18.83 %), 1,8-cineole (14.14 %), viridiflorol (7.98 %), β-thujone (4.46 %) and β-caryophyllene (3.30 %) as the major components, determined by gas chromatography-mass spectrometry. The level of antioxidant activity, determined by complementary tests, namely 2,2-diphenyl-1-picrylhydrazyl radical-scavenging (IC50= 6.7 mg/mL), linoleic acid peroxidation (IC50= 9.6 mg/mL) and ferric reducing assays (IC50= 28.4 mg/mL), was relatively moderate. The SoEO was also screened for its antimicrobial activity. Good to moderate inhibitions were recorded for most of tested microorganisms. It also exhibited important insecticidal activity against Spodoptera littoralis larvae and Tribolium castaneum adults with LC50 values of 55.99 and 97.43 µl/L air, respectively. The effect of the SoEO on seeds germination and growth showed different activities against radical and hypocotyl elongation of the tested species. These results suggest the potential use of the SoEO as natural antimicrobial preservative in cosmetic, pharmaceutical industry and in pest management. PMID:28507464

DNA/RNA binding and anticancer/antimicrobial activities of polymer-copper(II) complexes

NASA Astrophysics Data System (ADS)

Lakshmipraba, Jagadeesan; Arunachalam, Sankaralingam; Riyasdeen, Anvarbatcha; Dhivya, Rajakumar; Vignesh, Sivanandham; Akbarsha, Mohammad Abdulkader; James, Rathinam Arthur

2013-05-01

Water soluble polymer-copper(II) complexes with various degrees of coordination in the polymer chain were synthesized and characterized by elemental analysis, IR, UV-visible and EPR spectra. The DNA/RNA binding behavior of these polymer-copper(II) complexes was examined by UV-visible absorption, emission and circular dichroism spectroscopic methods, and cyclic voltammetry techniques. The binding of the polymer-copper(II) complexes with DNA/RNA was mainly through intercalation but some amount of electrostatic interaction was also observed. This binding capacity increased with the degree of coordination of the complexes. The polymer-copper(II) complex having the highest degree of coordination was subjected to analysis of cytotoxic and antimicrobial properties. The cytotoxicity study indicated that the polymer-copper(II) complexes affected the viability of MCF-7 mammary carcinoma cells, and the cells responded to the treatment with mostly through apoptosis although a few cells succumbed to necrosis. The antimicrobial screening showed activity against some human pathogens.

Structural, textural and morphological characteristics of tannins from Acacia mearnsii encapsulated using sol-gel methods: Applications as antimicrobial agents.

PubMed

Dos Santos, Cristiane; Vargas, Álvaro; Fronza, Ney; Dos Santos, João Henrique Zimnoch

2017-03-01

Tannins from Acacia mearnsii were encapsulated using four different sol-gel methods acid (SGAR), basic (SGBR), silicate (SGSR) and non-hydrolytic (SGNHR) routes. The hybrid materials were analyzed using a set of techniques to characterize their structure, texture and morphology. The antimicrobial performance of the encapsulated materials was evaluated against different microorganisms (Staphylococcus aureus, Escherichia coli, Aspergillus niger and Candida sp.). The data showed that the encapsulation route significantly affects the characteristics of the resulting hybrid materials. Better functional performances were obtained using the silicate route, which produced mesoporous materials with a small surface area (0.96m 2 g -1 ) and small particle size (<1nm). These characteristics promoted the gradual release of tannins in an aqueous medium and improved their interactions with microorganisms. Furthermore, the process demonstrated the preservation of tannins after synthesis and increased antimicrobial activity (via a controlled tannin release), as demonstrated by the moderate activity against filamentous fungi and yeast. Copyright © 2016. Published by Elsevier B.V.

Preparation and Properties of Electrospun Poly (Vinyl Pyrrolidone)/Cellulose Nanocrystal/Silver Nanoparticle Composite Fibers

PubMed Central

Huang, Siwei; Zhou, Ling; Li, Mei-Chun; Wu, Qinglin; Kojima, Yoichi; Zhou, Dingguo

2016-01-01

Poly (vinyl pyrrolidone) (PVP)/cellulose nanocrystal (CNC)/silver nanoparticle composite fibers were prepared via electrospinning using N,N′-dimethylformamide (DMF) as a solvent. Rheology, morphology, thermal properties, mechanical properties, and antimicrobial activity of nanocomposites were characterized as a function of material composition. The PVP/CNC/Ag electrospun suspensions exhibited higher conductivity and better rheological properties compared with those of the pure PVP solution. The average diameter of the PVP electrospun fibers decreased with the increase in the amount of CNCs and Ag nanoparticles. Thermal stability of electrospun composite fibers was decreased with the addition of CNCs. The CNCs help increase the composite tensile strength, while the elongation at break decreased. The composite fibers included Ag nanoparticles showed improved antimicrobial activity against both the Gram-negative bacterium Escherichia coli (E. coli) and the Gram-positive bacterium Staphylococcus aureus (S. aureus). The enhanced strength and antimicrobial performances of PVP/CNC/Ag electrospun composite fibers make the mat material an attractive candidate for application in the biomedical field. PMID:28773644

Metal complexes of the fourth generation quinolone antimicrobial drug gatifloxacin: Synthesis, structure and biological evaluation

NASA Astrophysics Data System (ADS)

Sadeek, Sadeek A.; El-Shwiniy, Walaa H.

2010-08-01

Three metal complexes of the fourth generation quinolone antimicrobial agent gatifloxacin (GFLX) with Y(ΙΙΙ), Zr(ΙV) and U(VΙ) have been prepared and characterized with physicochemical and spectroscopic techniques. In these complexes, gatifloxacin acts as a bidentate deprotonated ligand bound to the metal through the ketone oxygen and a carboxylato oxygen. The complexes are six-coordinated with distorted octahedral geometry. The kinetic parameters for gatifloxacin and the three prepared complexes have been evaluated from TGA curves by using Coats-Redfern (CR) and Horowitz-Metzeger (HM) methods. The calculated bond length and force constant, F(U dbnd O), for the UO 2 bond in uranyl complex are 1.7522 Å and 639.46 N m -1. The antimicrobial activity of the complexes has been tested against microorganisms, three bacterial species, such as Staphylococcus aureus ( S. aureus), Escherichia coli ( E. coli) and Pseudomonas aeruginosa ( P. aeruginosa) and two fungi species, penicillium ( P. rotatum) and trichoderma ( T. sp.), showing that they exhibit higher activity than free ligand.

Development and characterization of novel antimicrobial bilayer films based on Polylactic acid (PLA)/Pickering emulsions.

PubMed

Zhu, Jun-You; Tang, Chuan-He; Yin, Shou-Wei; Yang, Xiao-Quan

2018-02-01

Biodegradable food packaging is sustainable and has a great application prospect. PLA is a promising alternative for petroleum-derived polymers. However, PLA packaging suffers from poor barrier properties compared with petroleum-derived ones. To address this issue, we designed bilayer films based on PLA and Pickering emulsions. The formed bilayer films were compact and uniform and double layers were combined firmly. This strategy enhanced mechanical resistance, ductility and moisture barrier of Pickering emulsion films, and concomitantly enhanced the oxygen barrier for PLA films. Thymol loadings in Pickering emulsion layer endowed them with antimicrobial and antioxidant activity. The release profile of thymol was well fitted with Fick's second law. The antimicrobial activity of the films depended on film types, and Pickering emulsion layer presented larger inhibition zone than PLA layer, hinting that the films possessed directional releasing role. This study opens a promising route to fabricate bilayer architecture creating synergism of each layer. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improved antimicrobial compound production by a new isolate Streptomyces hygroscopicus MTCC 4003 using Plackett-Burman design and response Surface methodology.

PubMed

Singh, Neha; Rai, Vibhuti

2012-01-01

An active strain, isolated from soil of Chhattisgarh, India, showed broad-spectrum antimicrobial activity against various pathogenic bacteria and fungi in glucose soybean meal broth. Strain was characterized as Streptomyces hygroscopicus MTCC 4003 based on 16S rRNA sequencing from Microbial Type culture Collection (MTCC), IMTECH, Chandigarh, India. Identification of the purified antimicrobial compound was done by using Infra-red (IR), Mass, Ultraviolet (UV), 1H and 13C nuclear magnetic resonance (NMR) spectra. Plackett-Burman design (PBD) and response surface methodology (RSM) methods were used for the optimization of antibiotic production. Effects of the four medium components soybean meal, glucose, CaCO3 and MgSO4 showed positive effect on antibiotic production, were investigated with the help of PBD. The individual and interaction effects of the selected variables were determined by RSM using central composite design (CCD). Applying statistical design, antibiotic production was improved nearly ten times (412 mg/L) compared with unoptimized production medium (37 mg/L).

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

PubMed Central

Upadhyaya, Indu; Kollanoor-Johny, Anup

2014-01-01

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

Synthesis and anti-microbial potencies of 1-(2-hydroxyethyl)-3-alkylimidazolium chloride ionic liquids: microbial viabilities at different ionic liquids concentrations.

PubMed

Hossain, M Ismail; El-Harbawi, Mohanad; Alitheen, Noorjahan Banu Mohamed; Noaman, Yousr Abdulhadi; Lévêque, Jean-Marc; Yin, Chun-Yang

2013-01-01

Three 1-(2-hydroxyethyl)-3-alkylimidazolium chloride room temperature ionic liquids (ILs) [2OHimC(n)][Cl]; (n=0, 1, 4) have been synthesized from the appropriate imidazole precursors and characterized by IR and NMR spectroscopies and elemental analysis. Their anti-microbial activities were investigated using the well-diffusion method. The viabilities of Escherichia coli, Aeromonas hydrophila, Listeria monocytogenes and Salmonella enterica as a function of IL concentrations were studied. The minimal inhibitory concentrations (MICs) and EC₅₀ values for the present ILs were within the concentration range from 60 to 125 mM and 23 to 73 mM. The anti-microbial potencies of the present ILs were compared to a standard antibiotic, gentamicin. The finding affords additional perspective on the level of ILs toxicity to aquatic lifeforms and yet, this characteristic can be readily harnessed to detect microbial growth and activity. Copyright © 2012 Elsevier Inc. All rights reserved.

Antagonistic Properties of Some Halophilic Thermoactinomycetes Isolated from Superficial Sediment of a Solar Saltern and Production of Cyclic Antimicrobial Peptides by the Novel Isolate Paludifilum halophilum

PubMed Central

Frikha Dammak, Donyez; Zarai, Ziad; Najah, Soumaya; Abdennabi, Rayed; Belbahri, Lassaad; Rateb, Mostafa E.; Mejdoub, Hafedh

2017-01-01

This study has focused on the isolation of twenty-three halophilic actinomycetes from two ponds of different salinity and the evaluation of their ability to exert an antimicrobial activity against both their competitors and several other pathogens. From the 23 isolates, 18 strains showed antagonistic activity, while 19 showed activities against one or more of the seven pathogen strains tested. Six strains exhibited consistent antibacterial activity against Gram-negative and Gram-positive pathogens characterized at the physiological and molecular levels. These strains shared only 94-95% 16S rRNA sequence identity with the closely related species of the Thermoactinomycetaceae family. Among them, the potent strain SMBg3 was further characterized and assigned to a new genus in the family for which the name Paludifilum halophilum (DSM 102817T) is proposed. Sequential extraction of the antimicrobial compounds with ethyl acetate revealed that the crude extract from SMBg3 strain had inhibitory effect on the growth of the plant pathogen Agrobacterium tumefaciens and the human pathogens Staphylococcus aureus, Salmonella enterica, Escherichia coli, and Pseudomonas aeruginosa. Based on the HRESI-MS spectral data, the cyclic lipopeptide Gramicidin S and four cyclic dipeptides (CDPs) named cyclo(L-4-OH-Pro-L-Leu), cyclo(L-Tyr-L-Pro), cyclo(L-Phe-L-Pro), and cyclo(L-Leu-L-Pro) were detected in the fermentation broth of Paludifilum halophilum. To our knowledge, this is the first report on the isolation of these compounds from members of the Thermoactinomycetaceae family. PMID:28819625

Physico-chemical characteristics and antimicrobial studies of silver doped hydroxyapatite

NASA Astrophysics Data System (ADS)

Predoi, D.; Predoi, M. V.; Kettani, Moncef Ech Cherif El; Leduc, Damien; Iconaru, S. L.; Ciobanu, C. S.; Buton, N.; Petre, C. C.; Prodan, A. M.

2018-02-01

The present research is focused on the synthesis, structural and morphological characterization and antimicrobial evaluation of silver doped hydroxyapatite (AgHAp) in water. The preliminary ultrasonic characterizations of the AgHAp in water synthesized by an adapted co-precipitation method are also presented. X-ray diffraction result showed that silver ions were substituted in the hydroxyapatite structure. The lattice parameters increased when the silver substitution increased. The morphology of AgHAp were evaluated by Scanning Electron Microscopy (SEM). By EDX analysis the constituents elements of hydroxyapatite were detected in all analyzed samples. The silver was also found in the samples with xAg = 0.5 and 0.2. The colloidal properties of the resulted AgHAp (xAg = 0.0, 0.05 and 0.2) in water were analyzed by Dynamic Light Scattering (DLS) and zeta potential. On the other hand, the novelty of our research consists of preliminary ultrasonic measurements (US) conducted on AgHAp in water. Furthermore, the antimicrobial activity of AgHAp was evaluated and a decrease in the number of surviving cells was established.

Antibacterial activity of the emerging Fusarium mycotoxins enniatins A, A₁, A₂, B, B₁, and B₄ on probiotic microorganisms.

PubMed

Roig, M; Meca, G; Marín, R; Ferrer, E; Mañes, J

2014-07-01

Enniatins (ENs) are secondary metabolites produced by several Fusarium strains, chemically characterized as N-methylated cyclohexadepsipeptides. These compounds are known to act as antifungal and antibacterial agents, but they also possess anti-insect and phytotoxic properties. In this study, the antimicrobial effect of pure fractions of the bioactive compounds ENs A, A₁, A₂, B, B₁, and B₄ was tested towards nine probiotic microrganisms, twenty-two Saccharomyces cerevisiae strains and nine Bacillus subtilis strains. Antimicrobial analyses were carried out the disc-diffusion method using ENs concentrations ranging from 0.2 to 20,000 ng. Plates were incubated for 24 h at 37 °C before reading the diameter of the inhibition spots. ENs A, A₁, A₂, B, B₁ and B₄, were active against several microorganisms with inhibition halos ranging from 3 to 12 mm in diameter. The most active mycotoxin was the EN A₁, which reduced the microbial growth of 8 strains at the dose of 20,000 ng, with inhibition spots sized between 8 and 12 mm. ENs B and B₄ showed no antimicrobial activity towards the microorganisms tested at doses up to 20,000 ng per disc. Copyright © 2014 Elsevier Ltd. All rights reserved.

Antimicrobial and Antiproliferative Potential of Anadenanthera colubrina (Vell.) Brenan

PubMed Central

Lima, Rennaly de Freitas; Alves, Érika Ponchet; Rosalen, Pedro Luiz; Ruiz, Ana Lúcia Tasca Gois; Teixeira Duarte, Marta Cristina; Góes, Vivian Fernandes Furletti; de Medeiros, Ana Cláudia Dantas; Pereira, Jozinete Vieira; Godoy, Gustavo Pina; Melo de Brito Costa, Edja Maria

2014-01-01

The aim of the present study was to perform an in vitro analysis of the antimicrobial and antiproliferative potential of an extract from Anadenanthera colubrina (Vell.) Brenan (angico) and chemically characterize the crude extract. Antimicrobial action was evaluated based on the minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration, and the inhibition of formation to oral biofilm. Cell morphology was determined through scanning electron microscopy (SEM). Six strains of tumor cells were used for the determination of antiproliferative potential. The extract demonstrated strong antifungal activity against Candida albicans ATCC 18804 (MIC = 0.031 mg/mL), with similar activity found regarding the ethyl acetate fraction. The extract and active fraction also demonstrated the capacity to inhibit the formation of Candida albicans to oral biofilm after 48 hours, with median values equal to or greater than the control group, but the difference did not achieve statistical significance (P > 0.05). SEM revealed alterations in the cell morphology of the yeast. Regarding antiproliferative activity, the extract demonstrated cytostatic potential in all strains tested. The present findings suggest strong antifungal potential for Anadenanthera colubrina (Vell.) Brenan as well as a tendency toward diminishing the growth of human tumor cells. PMID:25093029

Template engineered biopotent macrocyclic complexes involving furan moiety: Molecular modeling and molecular docking

NASA Astrophysics Data System (ADS)

Rathi, Parveen; Singh, D. P.

2015-08-01

Bioactive cobalt(II), nickel(II), copper(II) and zinc(II) complexes of octaazamacrocycle, 19, 20-dioxa-2,3,5,6,11,12,14,15-octaazatricyclo[14.2.1.1]icosa-1,6,8,10,15,17-hexaene-4,13-dithione, derived from furan-2,5-dione and thiocarbonohydrazide in the mole ratio 2:2:1 have been engineered via template methodology. The synthesized metal complexes have also been structurally characterized in the light of various physicochemical techniques and evaluated for antimicrobial and antioxidant activities. All these studies point toward the formation of divalent macrocyclic complexes possessing distorted octahedral geometry and having significant antimicrobial and antioxidant properties as compared to the starting precursors. Virtual screening of a representative complex was done through docking to the binding site of COX-2 to evaluate the anti-inflammatory activity of the series. Non-electrolytic nature of the complexes has been predicted on the basis of low value of molar conductivity in DMSO. All the complexes were having notable activities against pathogenic microbes as compared to precursors-thiocarbonohydrazide and furan-2,5-dione however, the complex 5, [Ni (C10H8N8O2S2) (NO3)2], shows the best antimicrobial activity.

A review of fish-derived antioxidant and antimicrobial peptides: their production, assessment, and applications.

PubMed

Najafian, L; Babji, A S

2012-01-01

Fishes are rich sources of structurally diverse bioactive compounds. In recent years, much attention has been paid to the existence of peptides with biological activities and proteins derived from foods that might have beneficial effects for humans. Antioxidant and antimicrobial peptides isolated from fish sources may be used as functional ingredients in food formulations to promote consumer health and improve the shelf life of food products. This paper presents an overview of the antioxidant and antimicrobial peptides derived from various fishes. In addition, we discuss the extraction of fish proteins, enzymatic production, and the techniques used to isolate and characterize these compounds. Furthermore, we review the methods used to assay the bioactivities and their applications in food and nutraceuticals. Copyright © 2011 Elsevier Inc. All rights reserved.

Syntheses, Characterization, Resolution, and Biological Studies of Coordination Compounds of Aspartic Acid and Glycine

PubMed Central

Akinkunmi, Ezekiel; Ojo, Isaac; Adebajo, Clement; Isabirye, David

2017-01-01

Enantiomerically enriched coordination compounds of aspartic acid and racemic mixtures of coordination compounds of glycine metal-ligand ratio 1 : 3 were synthesized and characterized using infrared and UV-Vis spectrophotometric techniques and magnetic susceptibility measurements. Five of the complexes were resolved using (+)-cis-dichlorobis(ethylenediamine)cobalt(III) chloride, (+)-bis(glycinato)(1,10-phenanthroline)cobalt(III) chloride, and (+)-tris(1,10-phenanthroline)nickel(II) chloride as resolving agents. The antimicrobial and cytotoxic activities of these complexes were then determined. The results obtained indicated that aspartic acid and glycine coordinated in a bidentate fashion. The enantiomeric purity of the compounds was in the range of 22.10–32.10%, with (+)-cis-dichlorobis(ethylenediamine)cobalt(III) complex as the more efficient resolving agent. The resolved complexes exhibited better activity in some cases compared to the parent complexes for both biological activities. It was therefore inferred that although the increase in the lipophilicity of the complexes may assist in the permeability of the complexes through the cell membrane of the pathogens, the enantiomeric purity of the complexes is also of importance in their activity as antimicrobial and cytotoxic agents. PMID:28293149

Synthesis, characterization and antimicrobial activity of dextran sulphate stabilized silver nanoparticles

NASA Astrophysics Data System (ADS)

Cakić, Milorad; Glišić, Slobodan; Nikolić, Goran; Nikolić, Goran M.; Cakić, Katarina; Cvetinov, Miroslav

2016-04-01

Dextran sulphate stabilized silver nanoparticles (AgNPs - DS) were synthesized from aqueous solution of silver nitrate (AgNO3) and dextran sulphate sodium salt (DS). The characterization of AgNPs - DS was performed by ultraviolet-visible spectroscopy (UV-VIS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and antimicrobial activity. The formation of AgNPs - DS was monitored by colour changes of the reaction mixture from yellowish to brown and by measuring the surface plasmon resonance absorption peak in UV-VIS spectra at 420 nm. The SEM analysis was used for size and shape determination of AgNPs - DS. The presence of elemental silver and its crystalline structure in AgNPs - DS were confirmed by EDX and XRD analyses. The possible functional groups of DS responsible for the reduction and stabilization of AgNPs were determinated by FTIR spectroscopy. The AgNPs - DS showed strong antibacterial activity against Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 11778, Bacillus luteus in haus strain, Bacillus subtilis ATTC 6633, Listeria monocytogenes ATCC 15313, Escherichia coli ATTC 25922, Pseudomonas aeruginosa ATTC 27853, Klebsiella pneumoniae ATTC 700603, Proteus vulgaris ATTC 8427, and antifungal activity against Candida albicans ATTC 2091.

Synthesis, Characterization, Antimicrobial and Antioxidant Activities of The Homocyclotrimer Of 4-Oxo-4h-Thieno[3,4-C]Chromene-3-Diazonium Sulfate.

PubMed

Sopbue Fondjo, Emmanuel; Sorel, Djeukoua Dimo Kamal; Jean-de-Dieu, Tamokou; Joseph, Tsemeugne; Sylvian, Kouamo; Doriane, Ngouanet; Rodolphe, Chouna Jean; Pepin, Nkeng-Efouet-Alango; Jules-Roger, Kuiate; Arnaud, Ngongang Ndjintchui; Lucas, Sondengam Beibam

2016-01-01

The in situ formed 4-oxo-4H-thieno[3,4-c]chromene-3-diazonium sulfate (5) in the coupling reactions involving the parent 2-aminothiophene (4) and various phenolic and arylamines' couplers, readily undergoes homocyclotrimerization at low temperature to afford in fairly good yield the first ever reported eighteen member ring heteroaromatic holigomer 6. Compound 6 was fully characterized by its elemental analysis, IR, UV-Vis, (1)H-NMR, (13)C-NMR and HRMS spectral data. The HMBC and HSQC techniques were used to ascertain the structural assignments. A comparative study on the antimicrobial and antioxidant activities of compounds 3, 4 and 6 was carried out to assess the SAR due to the transformations (from 3 to 6 via 4) on the tested compounds. It was found that compounds 6 and 4 were respectively the most active compounds against bacteria (MIC = 32-64 μg/ml) and yeasts (MIC = 16-64 μg/ml). Compound 6 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and BHT used as reference antioxidants.

Synthesis, Characterization, Antimicrobial and Antioxidant Activities of The Homocyclotrimer Of 4-Oxo-4h-Thieno[3,4-C]Chromene-3-Diazonium Sulfate

PubMed Central

Sopbue Fondjo, Emmanuel; Sorel, Djeukoua Dimo Kamal; Jean-de-Dieu, Tamokou; Joseph, Tsemeugne; Sylvian, Kouamo; Doriane, Ngouanet; Rodolphe, Chouna Jean; Pepin, Nkeng-Efouet-Alango; Jules-Roger, Kuiate; Arnaud, Ngongang Ndjintchui; Lucas, Sondengam Beibam

2016-01-01

The in situ formed 4-oxo-4H-thieno[3,4-c]chromene-3-diazonium sulfate (5) in the coupling reactions involving the parent 2-aminothiophene (4) and various phenolic and arylamines’ couplers, readily undergoes homocyclotrimerization at low temperature to afford in fairly good yield the first ever reported eighteen member ring heteroaromatic holigomer 6. Compound 6 was fully characterized by its elemental analysis, IR, UV-Vis, 1H-NMR, 13C-NMR and HRMS spectral data. The HMBC and HSQC techniques were used to ascertain the structural assignments. A comparative study on the antimicrobial and antioxidant activities of compounds 3, 4 and 6 was carried out to assess the SAR due to the transformations (from 3 to 6 via 4) on the tested compounds. It was found that compounds 6 and 4 were respectively the most active compounds against bacteria (MIC = 32-64 μg/ml) and yeasts (MIC = 16–64 μg/ml). Compound 6 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and BHT used as reference antioxidants. PMID:27583034

Development of New Therapeutics Targeting Biofilm Formation by the Opportunistic Pulmonary Pathogens Pseudomonas aeruginosa and Aspergillus Fumigatus

DTIC Science & Technology

2017-10-01

antibacterial activity . The unexpected departure of PDF Perrin Baker in early June 2017 and the delay in recruiting his...characterize the ability of recombinant GH enzymes to enhance the activity of antimicrobial agents against PA and AF in vitro (2) Perform...major goals of the project as stated in the approved SOW. If the application listed milestones/target dates for important activities

Characterization of the volatile composition of essential oils of some lamiaceae spices and the antimicrobial and antioxidant activities of the entire oils.

PubMed

Bozin, Biljana; Mimica-Dukic, Neda; Simin, Natasa; Anackov, Goran

2006-03-08

The essential oils of Ocimum basilicum L., Origanum vulgare L., and Thymus vulgaris L. were analyzed by means of gas chromatography-mass spectrometry and assayed for their antioxidant and antimicrobial activities. The antioxidant activity was evaluated as a free radical scavenging capacity (RSC), together with effects on lipid peroxidation (LP). RSC was assessed measuring the scavenging activity of the essential oils on 2,2-diphenyl-1-picrylhydrazil (DPPH(*)) and OH(*) radicals. Effects on LP were evaluated following the activities of essential oils in Fe(2+)/ascorbate and Fe(2+)/H(2)O(2) systems of induction. Essential oils exhibited very strong RSCs, reducing the DPPH radical formation (IC(50)) in the range from 0.17 (oregano) to 0.39 microg/mL (basil). The essential oil of T. vulgaris exhibited the highest OH radical scavenging activity, although none of the examined essential oils reached 50% of neutralization (IC(50)). All of the tested essential oils strongly inhibited LP, induced either by Fe(2+)/ascorbate or by Fe(2+)/H(2)O(2). The antimicrobial activity was tested against 13 bacterial strains and six fungi. The most effective antibacterial activity was expressed by the essential oil of oregano, even on multiresistant strains of Pseudomonas aeruginosa and Escherichia coli. A significant rate of antifungal activity of all of the examined essential oils was also exhibited.

Honey: its medicinal property and antibacterial activity

PubMed Central

Mandal, Manisha Deb; Mandal, Shyamapada

2011-01-01

Indeed, medicinal importance of honey has been documented in the world's oldest medical literatures, and since the ancient times, it has been known to possess antimicrobial property as well as wound-healing activity. The healing property of honey is due to the fact that it offers antibacterial activity, maintains a moist wound condition, and its high viscosity helps to provide a protective barrier to prevent infection. Its immunomodulatory property is relevant to wound repair too. The antimicrobial activity in most honeys is due to the enzymatic production of hydrogen peroxide. However, another kind of honey, called non-peroxide honey (viz., manuka honey), displays significant antibacterial effects even when the hydrogen peroxide activity is blocked. Its mechanism may be related to the low pH level of honey and its high sugar content (high osmolarity) that is enough to hinder the growth of microbes. The medical grade honeys have potent in vitro bactericidal activity against antibiotic-resistant bacteria causing several life-threatening infections to humans. But, there is a large variation in the antimicrobial activity of some natural honeys, which is due to spatial and temporal variation in sources of nectar. Thus, identification and characterization of the active principle(s) may provide valuable information on the quality and possible therapeutic potential of honeys (against several health disorders of humans), and hence we discussed the medicinal property of honeys with emphasis on their antibacterial activities. PMID:23569748

Polyethylene Films Containing Silver Nanoparticles for Applications in Food Packaging: Characterization of Physico-Chemical and Anti-Microbial Properties.

PubMed

Becaro, Aline A; Puti, Fernanda C; Correa, Daniel S; Paris, Elaine C; Marconcini, José M; Ferreira, Marcos D

2015-03-01

This paper reports the antibacterial effect and physico-chemical characterization of films containing silver nanoparticles for use as food packaging. Two masterbatches (named PEN and PEC) con- taining silver nanoparticles embedded in distinct carriers (silica and titanium dioxide) were mixed with low-density polyethylene (LDPE) in different compositions and extruded to produce plain films. These films were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC), Thermogravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR). The morphology of the films showed the formation of agglomerates of nanoparticles in both PEN and PEC composites. X-ray analyses confirmed the presence of SiO2 in PEN samples and TiO2 in PEC samples. Thermal analyses indicated an increase in thermal stability of the PEC compositions. The antimicrobial efficacy was determined by applying the test strain for Escherichia coli and Staphylococcus aureus, according to the Japanese Industrial Standard Method (JIS Z 2801:2000). The films analyzed showed antimicrobial properties against the tested microorganisms, presenting better activity against the S. aureus than E. Coli. These findings suggest that LDPE films with silver nanoparticles are promising to provide a significant contribution to the quality and safety of packaged food.

Binary grafted chitosan film: Synthesis, characterization, antibacterial activity and prospects for food packaging.

PubMed

Kumar, Deepak; Kumar, Pramendra; Pandey, Jyoti

2018-04-17

The antimicrobial binary grafted chitosan film [chit-g-Poly (An-co-Am)] was prepared by grafting of acrylonitrile and acrylamide on to chitosan via microwave initiated graft copolymerization. The grafting of acrylonitrile and acrylamide onto chitosan backbone was confirmed by FTIR, XRD, SEM and TGA/DTA/DTG analytical techniques. The binary grafted chitosan film possessed efficient antimicrobial activity against three tested strains, i.e. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The prepared binary grafted chitosan film was tested for packaging apple and guava to prevent microbial infection and extend their shelf life. The biodegradability study of binary grafted chitosan film was also done and all the results were positive. Copyright © 2018. Published by Elsevier B.V.

Purification and Characterization of a Novel Anti-Campylobacter Bacteriocin Produced by Lactobacillus curvatus DN317.

PubMed

Zommiti, Mohamed; Almohammed, Hamdan; Ferchichi, Mounir

2016-12-01

The lactic acid bacteria (LAB) microbiota of Saudi chicken ceca was determined. From 60 samples, 204 isolates of lactic acid bacteria were obtained. Three isolates produced antimicrobial activities against Campylobacter jejuni, Listeria monocytogenes, and Bacillus subtilis. The isolate DN317, which had the highest activity against Campylobacter jejuni ATCC 33560, was identified as Lactobacillus curvatus (GenBank accession numbers: KX353849 and KX353850). Full inhibitory activity was observed after a 2-h incubation with the supernatant at pH values between 4 and 8. Only 16% of the activity was conserved after a treatment at 121 °C for 15 min. The use of proteinase K, pepsin, chymotrypsin, trypsin, papain, and lysozyme drastically reduced the antimicrobial activity. However, lipase, catalase, and lysozyme had no effect on this activity. The active peptide produced by Lactobacillus curvatus DN317 was purified by precipitation with an 80% saturated ammonium sulfate solution, and two steps of reversed phase HPLC on a C18 column. The molecular weight of this peptide was 4448 Da as determined by MALDI-ToF. N-terminal sequence analysis using Edman degradation revealed 47 amino acid residues (UniProt Knowledgebase accession number C0HK82) revealing homology with the amino acid sequences of sakacin P and curvaticin L442. The antimicrobial activity of the bacteriocin, namely curvaticin DN317, was found to be bacteriostatic against Campylobacter jejuni ATCC 33560. The use of microbial antagonism by LAB is one of the best ways to control microorganisms safely in foods. This result constitutes a reasonable advance in the antimicrobial field because of its potential applications in food technology.

Identification, Characterization, and Recombinant Expression of Epidermicin NI01, a Novel Unmodified Bacteriocin Produced by Staphylococcus epidermidis That Displays Potent Activity against Staphylococci

PubMed Central

Sandiford, Stephanie

2012-01-01

We describe the discovery, purification, characterization, and expression of an antimicrobial peptide, epidermicin NI01, which is an unmodified bacteriocin produced by Staphylococcus epidermidis strain 224. It is a highly cationic, hydrophobic, plasmid-encoded peptide that exhibits potent antimicrobial activity toward a wide range of pathogenic Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA), enterococci, and biofilm-forming S. epidermidis strains. Purification of the peptide was achieved using a combination of hydrophobic interaction, cation exchange, and high-performance liquid chromatography (HPLC). Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) analysis yielded a molecular mass of 6,074 Da, and partial sequence data of the peptide were elucidated using a combination of tandem mass spectrometry (MS/MS) and de novo sequencing. The draft genome sequence of the producing strain was obtained using 454 pyrosequencing technology, thus enabling the identification of the structural gene using the de novo peptide sequence data previously obtained. Epidermicin NI01 contains 51 residues with four tryptophan and nine lysine residues, and the sequence showed approximately 50% identity to peptides lacticin Z, lacticin Q, and aureocin A53, all of which belong to a new family of unmodified type II-like bacteriocins. The peptide is active in the nanomolar range against S. epidermidis, MRSA isolates, and vancomycin-resistant enterococci. Other unique features displayed by epidermicin include a high degree of protease stability and the ability to retain antimicrobial activity over a pH range of 2 to 10, and exposure to the peptide does not result in development of resistance in susceptible isolates. In this study we also show the structural gene alone can be cloned into Escherichia coli strain BL21(DE3), and expression yields active peptide. PMID:22155816

Antibacterial Activity, Antioxidant Effect and Chemical Composition of Propolis from the Región del Maule, Central Chile.

PubMed

Nina, Nélida; Quispe, Cristina; Jiménez-Aspee, Felipe; Theoduloz, Cristina; Feresín, Gabriela Egly; Lima, Beatriz; Leiva, Elba; Schmeda-Hirschmann, Guillermo

2015-10-06

Propolis is commercialized in Chile as an antimicrobial agent. It is obtained mainly from central and southern Chile, but is used for the same purposes regardless of its origin. To compare the antimicrobial effect, the total phenolic (TP), the total flavonoid (TF) content and the phenolic composition, 19 samples were collected in the main production centers in the Región del Maule, Chile. Samples were extracted with MeOH and assessed for antimicrobial activity against Gram (+) and Gram (-) bacteria. TP and TF content, antioxidant activity by the DPPH, FRAP and TEAC methods were also determined. Sample composition was assessed by HPLD-DAD-ESI-MS/MS. Differential compounds in the samples were isolated and characterized. The antimicrobial effect of the samples showed MICs ranging from 31.5 to > 1000 µg/mL. Propolis from the central valley was more effective as antibacterial than those from the coastal area or Andean slopes. The samples considered of interest (MIC ≤ 62.5 µg/mL) showed effect on Escherichia coli, Pseudomonas sp., Yersinia enterocolitica and Salmonella enteritidis. Two new diarylheptanoids, a diterpene, the flavonoids pinocembrin and chrysin were isolated and elucidated by spectroscopic and spectrometric means. Some 29 compounds were dereplicated by HPLC-MS and tentatively identified, including nine flavones/flavonol derivatives, one flavanone, eight dihydroflavonols and nine phenyl-propanoids. Propolis from the Región del Maule showed large variation in antimicrobial effect, antioxidant activity and composition. So far the presence of diarylheptanoids in samples from the coastal area of central Chile can be considered as a marker of a new type of propolis.

Membrane-Active Epithelial Keratin 6A Fragments (KAMPs) Are Unique Human Antimicrobial Peptides with a Non-αβ Structure

PubMed Central

Lee, Judy T. Y.; Wang, Guangshun; Tam, Yu Tong; Tam, Connie

2016-01-01

Antibiotic resistance is a pressing global health problem that threatens millions of lives each year. Natural antimicrobial peptides and their synthetic derivatives, including peptoids and peptidomimetics, are promising candidates as novel antibiotics. Recently, the C-terminal glycine-rich fragments of human epithelial keratin 6A were found to have bactericidal and cytoprotective activities. Here, we used an improved 2-dimensional NMR method coupled with a new protocol for structural refinement by low temperature simulated annealing to characterize the solution structure of these kerain-derived antimicrobial peptides (KAMPs). Two specific KAMPs in complex with membrane mimicking sodium dodecyl sulfate (SDS) micelles displayed amphipathic conformations with only local bends and turns, and a central 10-residue glycine-rich hydrophobic strip that is central to bactericidal activity. To our knowledge, this is the first report of non-αβ structure for human antimicrobial peptides. Direct observation of Staphylococcus aureus and Pseudomonas aeruginosa by scanning and transmission electron microscopy showed that KAMPs deformed bacterial cell envelopes and induced pore formation. Notably, in competitive binding experiments, KAMPs demonstrated binding affinities to LPS and LTA that did not correlate with their bactericidal activities, suggesting peptide-LPS and peptide-LTA interactions are less important in their mechanisms of action. Moreover, immunoprecipitation of KAMPs-bacterial factor complexes indicated that membrane surface lipoprotein SlyB and intracellular machineries NQR sodium pump and ribosomes are potential molecular targets for the peptides. Results of this study improve our understanding of the bactericidal function of epithelial cytokeratin fragments, and highlight an unexplored class of human antimicrobial peptides, which may serve as non-αβ peptide scaffolds for the design of novel peptide-based antibiotics. PMID:27891122

In vitro evaluation of cytotoxic, anti-proliferative, anti-oxidant, apoptotic, and anti-microbial activities of Cladonia pocillum.

PubMed

Ersoz, M; Coskun, Z M; Acikgoz, B; Karalti, I; Cobanoglu, G; Cesal, C

2017-08-15

The aim of this study was to investigate the anti-proliferative, apoptotic, cytotoxic, and anti-oxidant effects of extracts from the lichen Cladonia pocillumon human breast cancer cells (MCF-7), and to characterize the anti-microbial features.  MCF-7 cells were treated with methanolic C. pocillum extract for 24h. The cytotoxicity of the extract was tested with MTT. Moreover, its anti-proliferative effects were examined with immunocytochemical method. Apoptosis and biochemical parameters were detected in MCF-7. The methanol and chloroform extracts of the lichen were tested for anti-microbial activity against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans using the disc diffusion method and calculation of minimal inhibitory concentrations. Although BrdU incorporation was not observed in MCF-7 cells treated with methanol extract at a concentration above 0.2 mg/mL, a significant decrease was observed int he percentage of PCNA immunoreactive cells in groups treated with 0.2, 0.4, 06, and 0.8 mg/mL methanol extracts of C.pocillum (49±6.3, 44±5.2, 23±2.5, 0, respectively) compared to that of control (85±4.5). The percentage of apoptotic cells significantly increased in groups treated with 0.2, 0.4, 0.6, and 0.8 mg/mL extracts of the C.pocillum (54±3.5, 76±2.6, 77±1.8, 82±4.2, respectively) compared with that of control group (3.9±1.5).The half-maximal inhibitory concentration of the methanol extract against MCF-7 cells was 0.802 mg/mL .Although the chloroform extract showed more effective anti-microbial activity overall, the methanol extract showed higher anti-fungal activity. Collectively, the results of our study indicate that C.pocillum extracts have strong anti-microbial and apoptotic effects. This lichen therefore shows potential for development as a natural anti-microbial, anti-oxidant, and apoptotic agent.

Evaluation of antimicrobial activity of silver nanoparticles synthesized from Piper betle leaves against human and plant pathogens

NASA Astrophysics Data System (ADS)

Jha, Babita; Rao, Mugdha; Prasad, K.; Jha, Anal K.

2018-05-01

The present work encompasses the fabrication of biocompatible silver nanoparticles from the leaves of the medicinal plant Piper betle using green chemistry approach. The synthesized nanoparticles were characterized by different standard techniques like: UV-visible spectroscopy, X-ray diffraction, scanning electron microscopy and Fourier transformed infrared spectroscopy. The antimicrobial efficacy of the silver nanoparticles was assessed against human and plant pathogens namely Ralstonia solanacearum, Burkholderia gladioli, Escherichia coli and Sacchromyces cerevisiae by agar well diffusion method. The obtained results clearly indicate its possible use as an alternative to antibiotics and pesticides in near future.

Synthesized zinc peroxide nanoparticles (ZnO2-NPs): a novel antimicrobial, anti-elastase, anti-keratinase, and anti-inflammatory approach toward polymicrobial burn wounds

PubMed Central

El-Zawawy, Nessma Ahmed; Fareed, Mervat F; Bedaiwy, Mohamed Yaser

2017-01-01

Increasing of multidrug resistance (MDR) remains an intractable challenge for burn patients. Innovative nanomaterials are also in high demand for the development of new antimicrobial biomaterials that inevitably have opened new therapeutic horizons in medical approaches and lead to many efforts for synthesizing new metal oxide nanoparticles (NPs) for better control of the MDR associated with the polymicrobial burn wounds. Recently, it seems that metal oxides can truly be considered as highly efficient inorganic agents with antimicrobial properties. In this study, zinc peroxide NPs (ZnO2-NPs) were synthesized using the co-precipitation method. Synthesized ZnO2-NPs were characterized by X-ray diffraction, Fourier transformed infrared, transmission electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and ultraviolet-visible spectroscopy. The characterization techniques revealed synthesis of the pure phase of non-agglomerated ZnO2-NPs having sizes in the range of 15–25 nm with a transition temperature of 211°C. Antimicrobial activity of ZnO2-NPs was determined against MDR Pseudomonas aeruginosa (PA) and Aspergillus niger (AN) strains isolated from burn wound infections. Both strains, PA6 and AN4, were found to be more susceptible strains to ZnO2-NPs. In addition, a significant decrease in elastase and keratinase activities was recorded with increased concentrations of ZnO2-NPs until 200 µg/mL. ZnO2-NPs revealed a significant anti-inflammatory activity against PA6 and AN4 strains as demonstrated by membrane stabilization, albumin denaturation, and proteinase inhibition. Moreover, the results of in vivo histopathology assessment confirmed the potential role of ZnO2-NPs in the improvement of skin wound healing in the experimental animal models. Clearly, the synthesized ZnO2-NPs have demonstrated a competitive capability as antimicrobial, anti-elastase, anti-keratinase, and anti-inflammatory candidates, suggesting that the ZnO2-NPs are promising metal oxides that are potentially valued for biomedical applications. PMID:28860766

Bioactive formulations prepared from fruiting bodies and submerged culture mycelia of the Brazilian edible mushroom Pleurotus ostreatoroseus Singer.

PubMed

Corrêa, Rúbia Carvalho Gomes; de Souza, Aloisio Henrique Pereira; Calhelha, Ricardo C; Barros, Lillian; Glamoclija, Jasmina; Sokovic, Marina; Peralta, Rosane Marina; Bracht, Adelar; Ferreira, Isabel C F R

2015-07-01

Pleurotus ostreatoroseus is a Brazilian edible mushroom whose chemical characterization and bioactivity still remain underexplored. In this study, the hydrophilic and lipophilic compounds as well as the antioxidant, anti-inflammatory and antimicrobial activities of formulations (ethanol extracts) prepared with its fruiting bodies and submerged culture mycelia were compared. The bioactive formulations contain at least five free sugars, four organic acids, four phenolic compounds and two tocopherols. The fruiting body-based formulation revealed higher reducing power, DPPH scavenging activity, β-carotene bleaching inhibition and lipid peroxidation inhibition in brain homogenates than the mycelium-based preparation, as well as higher anti-inflammatory and antimicrobial activities. The absence of hepatotoxicity was confirmed in porcine liver primary cells. These functional responses can be related to the levels of bioactive components including phenolic acids, organic acids and tocopherols.

Synthesis, crystal structure and antimicrobial potential of some fluorinated chalcone-1,2,3-triazole conjugates.

PubMed

Yadav, Pinki; Lal, Kashmiri; Kumar, Lokesh; Kumar, Ashwani; Kumar, Anil; Paul, Avijit K; Kumar, Rajnish

2018-06-02

A simple and green synthesis of some fluorinated chalcone-triazole hybrids from propargylated chalcones and organic azides catalyzed by cellulose supported copper nanoparticles click reaction is reported. All the synthesized compounds were well characterized by various analytical and spectroscopic methods. The X-rays crystallographic study of compounds 6k revealed the self assembling properties. The antimicrobial screening results of all the synthesized compounds revealed that most of the triazole hybrids exhibited significant efficacy against tested bacterial and fungal strains. The activity results showed the synergistic effect of biological activity when two pharmacophoric units, i.e. chalcone and 1,2,3-triazole are conjugated. Further, docking simulation of the most active compounds 6p into Escherichia coli topoisomerase II DNA Gyrase B was also carried out. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Photo-induced green synthesis and antimicrobial efficacy of poly (ɛ-caprolactone)/curcumin/grape leaf extract-silver hybrid nanoparticles.

PubMed

El-Sherbiny, Ibrahim M; El-Shibiny, Ayman; Salih, Ehab

2016-07-01

This study reports the photo-induced green synthesis and antimicrobial assessment of poly(ɛ-caprolactone)/curcumin/grape leaf extract-Ag hybrid nanoparticles (PCL/Cur/GLE-Ag NPs). PCL/Cur/GLE NPs were synthesized via emulsion-solvent evaporation in the presence of PVA as a capping agent, then used as active nano-supports for the green synthesis and stabilization of AgNPs on their surfaces. Both Cur and GLE were selected and incorporated into the PCL nano-supports due to their reported promising antimicrobial activity that would further enhance that of the synthesized AgNPs. The developed PCL/Cur/GLE NPs and PCL/Cur/GLE-Ag hybrid NPs were characterized using UV-visible spectrophotometry, high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). HRTEM images showed that the PCL/Cur/GLE NPs are monodispersed and spherical with size of about 270nm, and the AgNPs were formed mainly on their surfaces with average size in the range 10-30nm. The synthesized AgNPs were found to be crystalline as shown by XRD patterns with fcc phase oriented along the (111), (200), (220) and (311) planes. The antimicrobial characteristics of the newly developed NPs were investigated against gram-positive and gram-negative bacteria in addition to two fungal strains. The results demonstrated that the PCL/Cur/GLE-Ag hybrid NPs have a potential antimicrobial activity against pathogenic bacterial species and could be considered as an alternative antibacterial agent. Copyright © 2016 Elsevier B.V. All rights reserved.

Antimicrobial and anticancer activities of porous chitosan-alginate biosynthesized silver nanoparticles.

PubMed

Venkatesan, Jayachandran; Lee, Jin-Young; Kang, Dong Seop; Anil, Sukumaran; Kim, Se-Kwon; Shim, Min Suk; Kim, Dong Gyu

2017-05-01

The main aim of this study was to obtain porous antimicrobial composites consisting of chitosan, alginate, and biosynthesized silver nanoparticles (AgNPs). Chitosan and alginate were used owing to their pore-forming capacity, while AgNPs were used for their antimicrobial property. The developed porous composites of chitosan-alginate-AgNPs were characterized using Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy, X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM). The FT-IR results revealed the presence of a strong chemical interaction between chitosan and alginate due to polyelectrolyte complex; whereas, the XRD results confirmed the presence of AgNPs in the composites. The dispersion of AgNPs in the porous membrane was uniform with a pore size of 50-500μm. Antimicrobial activity of the composites was checked with Escherichia coli and Staphylococcus aureus. The developed composites resulted in the formation of a zone of inhibition of 11±1mm for the Escherichia coli, and 10±1mm for Staphylococcus aureus. The bacterial filtration efficiency of chitosan-alginate-AgNPs was 1.5-times higher than that of the chitosan-alginate composite. The breast cancer cell line MDA-MB-231 was used to test the anticancer activity of the composites. The IC 50 value of chitosan-alginate-AgNPs on MDA-MB-231 was 4.6mg. The developed chitosan-alginate-AgNPs composite showed a huge potential for its applications in antimicrobial filtration and cancer treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Green synthesis of zero-valent Fe-nanoparticles: Catalytic degradation of rhodamine B, interactions with bovine serum albumin and their enhanced antimicrobial activities.

PubMed

Khan, Zaheer; Al-Thabaiti, Shaeel Ahmad

2018-03-01

Biomimetic method was used for the synthesis of Fe-nanoparticles (FeNPs). FeCl 3 and Hibiscus sabdariffa, Roselle flower aqueous extract (HBS) were employed in the present studies. The FeNPs have been characterized by using UV-visible spectroscopy, transmission electron microscope (TEM), and energy dispersion X-ray spectroscopy (EDS). The average particles diameter was found to be 18 nm. The as prepared FeNPs were used as a catalyst to the oxidative degradation of rhodamine B (RB) in presence of NaBH 4 . The effects of various quencher on the degradation rates were examined by employing ammonium oxalate (AO), benzoquinone (BQ), isopropyl alcohol (IPA), and potassium iodide (KI). The interactions of FeNPs with bovine serum albumin (BSA) have been determined and discussed. Adsorption of FeNPs into the core of BSA changes the tryptophan environment from hydrophobic to hydrophilic (from folding to partially folded and/or unfolded). Tryptophan residues, indole moieties of BSA were responsible to complex formation with FeNPs in excited states via electrostatic, van der Waals, hydrogen bonding, hydrophobic and hydrophilic interactions with static quenching. The antimicrobial activities of FeNPs have been determined against human pathogens. Hibiscus sabdariffa flower extract shows mild antimicrobial activities against all target pathogenic organisms. FeNPs have potential antimicrobial activity against both bacterial strains and candida fungus even at low concentration, and retains potential application in biomedical industries. Copyright © 2018 Elsevier B.V. All rights reserved.

Purification and characterization of peptides from Capsicum annuum fruits which are α-amylase inhibitors and exhibit high antimicrobial activity against fungi of agronomic importance.

PubMed

Dos Santos, Layrana de Azevedo; Taveira, Gabriel Bonan; Ribeiro, Suzanna de Fátima Ferreira; Pereira, Lídia da Silva; Carvalho, André de Oliveira; Rodrigues, Rosana; Oliveira, Antônia Elenir Amâncio; Machado, Olga Lima Tavares; Araújo, Jucélia da Silva; Vasconcelos, Ilka Maria; Gomes, Valdirene Moreira

2017-04-01

Proteins extracted from Capsicum annuum L. fruits were initially subjected to reversed-phase chromatography on HPLC, resulting in eight peptide-rich fractions. All the fractions obtained were tested for their ability to inhibit porcine trypsin and amylase from both human saliva and from larval insect in vitro. All fractions were also tested for their ability to inhibit growth of the phytopathogenic fungi. Several fractions inhibited the activity of human salivary amylase and larval insect amylase, especially fraction Fa5. No fraction tested was found to inhibit trypsin activity, being Fa2 fraction an exception. Interestingly fraction Fa5 also displayed high antimicrobial activity against the species of the Fusarium genus. Fraction Fa5 was found to have two major protein bands of 17 and 6.5 kDa, and these were sequenced by mass spectrometry. Two peptides were obtained from the 6.5-kDa band, which showed similarity to antimicrobial peptides. Fraction Fa5 was also tested for its ability to permeabilize membranes and induce ROS. Fraction Fa5 was able to permeabilize the membranes of all the fungi tested. Fungi belonging to the genus Fusarium also showed an increase in the endogenous production of ROS when treated with this fraction. Antimicrobial peptides were also identified in the fruits from other Capsicum species. Copyright © 2017 Elsevier Inc. All rights reserved.

Antimicrobial peptide hLF1-11 directs granulocyte-macrophage colony-stimulating factor-driven monocyte differentiation toward macrophages with enhanced recognition and clearance of pathogens.

PubMed

van der Does, Anne M; Bogaards, Sylvia J P; Ravensbergen, Bep; Beekhuizen, Henry; van Dissel, Jaap T; Nibbering, Peter H

2010-02-01

The human lactoferrin-derived peptide hLF1-11 displays antimicrobial activities in vitro and is effective against infections with antibiotic-resistant bacteria and fluconazole-resistant Candida albicans in animals. However, the mechanisms underlying these activities remain largely unclear. Since hLF1-11 is ineffective in vitro at physiological salt concentrations, we suggested modulation of the immune system as an additional mechanism of action of the peptide. We investigated whether hLF1-11 affects human monocyte-macrophage differentiation and determined the antimicrobial activities of the resulting macrophages. Monocytes were cultured for 7 days with GM-CSF in the presence of hLF1-11, control peptide, or saline for various intervals. At day 6, the cells were stimulated with lipopolysaccharide (LPS), lipoteichoic acid (LTA), or heat-killed C. albicans for 24 h. Thereafter, the levels of cytokines in the culture supernatants, the expression of pathogen recognition receptors, and the antimicrobial activities of these macrophages were determined. The results showed that a short exposure of monocytes to hLF1-11 during GM-CSF-driven differentiation is sufficient to direct differentiation of monocytes toward a macrophage subset characterized by both pro- and anti-inflammatory cytokine production and increased responsiveness to microbial structures. Moreover, these macrophages are highly effective against C. albicans and Staphylococcus aureus. In conclusion, hLF1-11 directs GM-CSF-driven differentiation of monocytes toward macrophages with enhanced effector functions.

Biosynthesis of silver nanoparticles using Plectranthus amboinicus leaf extract and its antimicrobial activity

NASA Astrophysics Data System (ADS)

Ajitha, B.; Ashok Kumar Reddy, Y.; Sreedhara Reddy, P.

2014-07-01

This study reports the simple green synthesis method for the preparation of silver nanoparticles (Ag NPs) using Plectranthus amboinicus leaf extract. The pathway of nanoparticles formation is by means of reduction of AgNO3 by leaf extract, which acts as both reducing and capping agents. Synthesized Ag NPs were subjected to different characterizations for studying the structural, chemical, morphological, optical and antimicrobial properties. The bright circular fringes in SAED pattern and diffraction peaks in XRD profile reveals high crystalline nature of biosynthesized Ag NPs. Morphological studies shows the formation of nearly spherical nanoparticles. FTIR spectrum confirms the existence of various functional groups of biomolecules capping the nanoparticles. UV-visible spectrum displays single SPR band at 428 nm indicating the absence of anisotropic particles. The synthesized Ag NPs exhibited better antimicrobial property towards gram negative Escherichia coli and towards tested Penicillium spp. than other tested microorganisms using disc diffusion method. Finally it has proven that the synthesized bio-inspired Ag NPs have potent antimicrobial effect.

In silico optimization of a guava antimicrobial peptide enables combinatorial exploration for peptide design.

PubMed

Porto, William F; Irazazabal, Luz; Alves, Eliane S F; Ribeiro, Suzana M; Matos, Carolina O; Pires, Állan S; Fensterseifer, Isabel C M; Miranda, Vivian J; Haney, Evan F; Humblot, Vincent; Torres, Marcelo D T; Hancock, Robert E W; Liao, Luciano M; Ladram, Ali; Lu, Timothy K; de la Fuente-Nunez, Cesar; Franco, Octavio L

2018-04-16

Plants are extensively used in traditional medicine, and several plant antimicrobial peptides have been described as potential alternatives to conventional antibiotics. However, after more than four decades of research no plant antimicrobial peptide is currently used for treating bacterial infections, due to their length, post-translational modifications or  high dose requirement for a therapeutic effect . Here we report the design of antimicrobial peptides derived from a guava glycine-rich peptide using a genetic algorithm. This approach yields guavanin peptides, arginine-rich α-helical peptides that possess an unusual hydrophobic counterpart mainly composed of tyrosine residues. Guavanin 2 is characterized as a prototype peptide in terms of structure and activity. Nuclear magnetic resonance analysis indicates that the peptide adopts an α-helical structure in hydrophobic environments. Guavanin 2 is bactericidal at low concentrations, causing membrane disruption and triggering hyperpolarization. This computational approach for the exploration of natural products could be used to design effective peptide antibiotics.

Synthesis, spectroscopic characterization and in vitro antimicrobial, anticancer and antileishmanial activities as well interaction with Salmon sperm DNA of newly synthesized carboxylic acid derivative, 4-(4-methoxy-2-nitrophenylamino)-4-oxobutanoic acid

NASA Astrophysics Data System (ADS)

Sirajuddin, Muhammad; Ali, Saqib; McKee, Vickie; Ullah, Hameed

2015-03-01

This paper stresses on the synthesis, characterization of novel carboxylic acid derivative and its application in pharmaceutics. Carboxylic acid derivatives have a growing importance in medicine, particularly in oncology. A novel carboxylic acid, 4-(4-methoxy-2-nitrophenylamino)-4-oxobutanoic acid, was synthesized and characterized by elemental analysis, FT-IR, NMR (1H, and 13C), mass spectrometry and single crystal X-ray structural analysis. The structure of the title compound, C11H12N2O6, shows the molecules dimerised by short intramolecular Osbnd H⋯O hydrogen bonds. The compound was screened for in vitro antimicrobial, anticancer, and antileishmanial activities as well as interaction with SS-DNA. The compound was also checked for in vitro anticancer activity against BHK-21, H-157 and HCEC cell lines, and showed significant anticancer activity. The compound was almost non-toxic towards human corneal epithelial cells (HCEC) and did not show more than 7.4% antiproliferative activity when used at the 2.0 μg/mL end concentration. It was also tested for antileishmanial activity against the promastigote form of leishmania major and obtained attractive result. DNA interaction study exposes that the binding mode of the compound with SS-DNA is an intercalative as it results in hypochromism along with minor red shift. A new and efficient strategy to identify pharmacophores sites in carboxylic acid derivative for antibacterial/antifungal activity using Petra, Osiris and Molinspiration (POM) analyses was also carried out.

Antimicrobial eugenol nanoemulsion prepared by gum arabic and lecithin and evaluation of drying technologies.

PubMed

Hu, Qiaobin; Gerhard, Hannah; Upadhyaya, Indu; Venkitanarayanan, Kumar; Luo, Yangchao

2016-06-01

The purpose of present work was to develop eugenol oil nanoemulsions using gum arabic and lecithin as food grade natural emulsifiers, and study their antimicrobial activity. In addition, our study also evaluated different drying techniques (spray drying and freeze drying) on the morphology and redispersibility of nanoemulsion powders. The optimal fabrication method, physicochemical and structural characterization, stability, and antimicrobial activity were investigated. Results showed that nanoemusions with a particle size of 103.6±7.5nm were obtained by mixing aqueous phase (0.5% gum arabic, 0.5% lecithin, w/v) and eugenol oil (1.25%, w/v), which was premixed with ethanol (as a co-surfactant), followed by high speed homogenization process. The molecular interactions among emulsifiers and eugenol were evidenced by Fourier transform infrared spectroscopy. Buchi B-90 Nano Spray Dryer was evaluated as a powerful tool to obtain ultrafine spherical powders with a size of less than 500nm, compared to flake-like aggregation obtained by freeze-drying. The dried powders exhibited excellent re-dispersibility in water and maintained their physicochemical properties after re-hydration. The nanoemulsions did not adversely affect the antimicrobial activity of eugenol against Listeria monocytogenes and Salmonella Enteritidis. Therefore, the nanoemulsions have the potential to be applied in the food industry as a food preservative or sanitizer. Copyright © 2016 Elsevier B.V. All rights reserved.

First Total Syntheses and Antimicrobial Evaluation of Penicimonoterpene, a Marine-Derived Monoterpenoid, and Its Various Derivatives

PubMed Central

Zhao, Jian-Chun; Li, Xiao-Ming; Gloer, James B.; Wang, Bin-Gui

2014-01-01

The first total synthesis of marine-derived penicimonoterpene (±)-1 has been achieved in four steps from 6-methylhept-5-en-2-one using a Reformatsky reaction as the key step to construct the basic carbon skeleton. A total of 24 new derivatives of 1 have also been designed and synthesized. Their structures were characterized by analysis of their 1H NMR, 13C NMR and HRESIMS data. Some of them showed significant antibacterial activity against Aeromonas hydrophila, Escherichia coli, Micrococcus luteus, Staphylococcus aureus, Vibrio anguillarum, V. harveyi and/or V. parahaemolyticus, and some showed activity against plant-pathogenic fungi (Alternaria brassicae, Colletotrichum gloeosporioides and/or Fusarium graminearum). Some of the derivatives exhibited antimicrobial MIC values ranging from 0.25 to 4 μg/mL, which were stronger than those of the positive control. Notably, Compounds 3b and 10 showed extremely high selectively against plant-pathogenic fungus F. graminearum (MIC 0.25 μg/mL) and pathogenic bacteria E. coli (MIC 1 μg/mL), implying their potential as antimicrobial agents. SAR analysis of 1 and its derivatives indicated that modification of the carbon-carbon double bond at C-6/7, of groups on the allylic methylene unit and of the carbonyl group at C-1, effectively enhanced the antimicrobial activity. PMID:24897384

Efficacy of Antimicrobial Agents for Food Contact Applications: Biological Activity, Incorporation into Packaging, and Assessment Methods: A Review.

PubMed

Mousavi Khaneghah, Amin; Hashemi, Seyed Mohammad Bagher; Eş, Ismail; Fracassetti, Daniela; Limbo, Sara

2018-07-01

Interest in the utilization of antimicrobial active packaging for food products has increased in recent years. Antimicrobial active packaging involves the incorporation of antimicrobial compounds into packaging materials, with the aim of maintaining or extending food quality and shelf life. Plant extracts, essential oils, organic acids, bacteriocins, inorganic substances, enzymes, and proteins are used as antimicrobial agents in active packaging. Evaluation of the antimicrobial activity of packaging materials using different methods has become a critical issue for both food safety and the commercial utilization of such packaging technology. This article reviews the different types of antimicrobial agents used for active food packaging materials, the main incorporation techniques, and the assessment methods used to examine the antimicrobial activity of packaging materials, taking into account their safety as food contact materials.

Characterization of Antibacterial and Hemolytic Activity of Synthetic Pandinin 2 Variants and Their Inhibition against Mycobacterium tuberculosis

PubMed Central

Rodríguez, Alexis; Villegas, Elba; Montoya-Rosales, Alejandra; Rivas-Santiago, Bruno; Corzo, Gerardo

2014-01-01

The contention and treatment of Mycobacterium tuberculosis and other bacteria that cause infectious diseases require the use of new type of antibiotics. Pandinin 2 (Pin2) is a scorpion venom antimicrobial peptide highly hemolytic that has a central proline residue. This residue forms a structural “kink” linked to its pore-forming activity towards human erythrocytes. In this work, the residue Pro14 of Pin2 was both substituted and flanked using glycine residues (P14G and P14GPG) based on the low hemolytic activities of antimicrobial peptides with structural motifs Gly and GlyProGly such as magainin 2 and ponericin G1, respectively. The two Pin2 variants showed antimicrobial activity against E. coli, S. aureus, and M. tuberculosis. However, Pin2 [GPG] was less hemolytic (30%) than that of Pin2 [G] variant. In addition, based on the primary structure of Pin2 [G] and Pin2 [GPG], two short peptide variants were designed and chemically synthesized keeping attention to their physicochemical properties such as hydrophobicity and propensity to adopt alpha-helical conformations. The aim to design these two short antimicrobial peptides was to avoid the drawback cost associated to the synthesis of peptides with large sequences. The short Pin2 variants named Pin2 [14] and Pin2 [17] showed antibiotic activity against E. coli and M. tuberculosis. Besides, Pin2 [14] presented only 25% of hemolysis toward human erythrocytes at concentrations as high as 100 µM, while the peptide Pin2 [17] did not show any hemolytic effect at the same concentration. Furthermore, these short antimicrobial peptides had better activity at molar concentrations against multidrug resistance M. tuberculosis than that of the conventional antibiotics ethambutol, isoniazid and rifampicin. Therefore, Pin2 [14] and Pin2 [17] have the potential to be used as an alternative antibiotics and anti-tuberculosis agents with reduced hemolytic effects. PMID:25019413

Insights into the anticancer properties of the first antimicrobial peptide from Archaea.

PubMed

Gaglione, Rosa; Pirone, Luciano; Farina, Biancamaria; Fusco, Salvatore; Smaldone, Giovanni; Aulitto, Martina; Dell'Olmo, Eliana; Roscetto, Emanuela; Del Gatto, Annarita; Fattorusso, Roberto; Notomista, Eugenio; Zaccaro, Laura; Arciello, Angela; Pedone, Emilia; Contursi, Patrizia

2017-09-01

The peptide VLL-28, identified in the sequence of an archaeal protein, the transcription factor Stf76 from Sulfolobus islandicus, was previously identified and characterized as an antimicrobial peptide, possessing a broad-spectrum antibacterial activity. Through a combined approach of NMR and Circular Dichroism spectroscopy, Dynamic Light Scattering, confocal microscopy and cell viability assays, the interaction of VLL-28 with the membranes of both parental and malignant cell lines has been characterized and peptide mechanism of action has been studied. It is here demonstrated that VLL-28 selectively exerts cytotoxic activity against murine and human tumor cells. By means of structural methodologies, VLL-28 interaction with the membranes has been proven and the binding residues have been identified. Confocal microscopy data show that VLL-28 is internalized only into tumor cells. Finally, it is shown that cell death is mainly caused by a time-dependent activation of apoptotic pathways. VLL-28, deriving from the archaeal kingdom, is here found to be endowed with selective cytotoxic activity towards both murine and human cancer cells and consequently can be classified as an ACP. VLL-28 represents the first ACP identified in an archaeal microorganism, exerting a trans-kingdom activity. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular analysis, biochemical characterization, antimicrobial activity and immunological analysis of proteus mirabilis isolated from broilers

USDA-ARS?s Scientific Manuscript database

Proteus mirabilis, a peritrichously flagellated Gram-negative bacterium, is ubiquitous in the environment and is the normal microflora in the human gastrointestinal tract. However, this bacterium is an opportunistic pathogen for human, often causing urinary tract infection. Moreover, Proteus has b...

Susceptibility of Escherichia coli isolated from uteri of postpartum dairy cows to antibiotic and environmental bacteriophages. Part II: In vitro antimicrobial activity evaluation of a bacteriophage cocktail and several antibiotics.

PubMed

Santos, T M A; Gilbert, R O; Caixeta, L S; Machado, V S; Teixeira, L M; Bicalho, R C

2010-01-01

The use of pathogenic-specific antimicrobials, as proposed by bacteriophage therapy, is expected to reduce the incidence of resistance development. Eighty Escherichia coli isolated from uteri of Holstein dairy cows were phenotypically characterized for antimicrobial resistance to ampicillin, ceftiofur, chloramphenicol, florfenicol, spectinomycin, streptomycin, and tetracycline by broth microdilution method. The lytic activity of a bacteriophage cocktail against all isolates was performed by a similar method. Additionally, the effect of different concentrations of antimicrobials and multiplicities of infections (MOI) of the bacteriophage cocktail on E. coli growth curve was measured. Isolates exhibited resistance to ampicillin (33.7%), ceftiofur (1.2%), chloramphenicol (100%), and florfenicol (100%). All strains were resistant to at least 2 of the antimicrobial agents tested; multidrug resistance (>or=3 of 7 antimicrobials tested) was observed in 35% of E. coli isolates. The major multidrug resistance profile was found for ampicillin-chloramphenicol-florfenicol, which was observed in more than 96.4% of the multidrug-resistant isolates. The bacteriophage cocktail preparation showed strong antimicrobial activity against multidrug-resistant E. coli. Multiplicity of infection as low as 10(-4) affected the growth of the E. coli isolates. The ratio of 10 bacteriophage particles per bacterial cell (MOI=10(1)) was efficient in inhibiting at least 50% of all isolates. Higher MOI should be tested in future in vitro studies to establish ratios that completely inhibit bacterial growth during longer periods. All isolates resistant to florfenicol were resistant to chloramphenicol and, because florfenicol was recently introduced into veterinary clinics, this finding suggests that the selection pressure of chloramphenicol, as well as other antimicrobials, may still play a relevant role in the emergence and dissemination of florfenicol resistance in E. coli. The bacteriophage cocktail had a notable capacity to inhibit the in vitro growth of E. coli isolates, and it may be an attractive alternative to conventional treatment of metritis by reducing E. coli in uteri of postpartum dairy cows. Copyright 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Evaluation of the cytotoxic effect and antibacterial, antifungal, and antiviral activities of Hypericum triquetrifolium Turra essential oils from Tunisia

PubMed Central

2013-01-01

Background A number of bio-active secondary metabolites have been identified and reported for several Hypericum species. Many studies have reported the potential use of the plant extracts against several pathogens. However, Hypericum triquetrifolium is one of the least studied species for its antimicrobial activity. The aim of the present study was to evaluate the cytotoxic effect of the essential oils of Hypericum triquetrifolium as well as their antimicrobial potential against coxsakievirus B3 and a range of bacterial and fungal strains. Methods The essential oils of Hypericum triquetrifolium harvested from five different Tunisian localities (Fondouk DJedid, Bou Arada, Bahra, Fernana and Dhrea Ben Jouder) were evaluated for their antimicrobial activities by micro-broth dilution methods against bacterial and fungal strains. In addition, the cytotoxic effect and the antiviral activity of these oils were carried out using Vero cell lines and coxsakievirus B3. Results The results showed a good antibacterial activities against a wide range of bacterial strains, MIC values ranging between 0.39-12.50 mg/ml and MBC values between 1.56-25.0 mg/ml. In addition, the essential oils showed promising antifungal activity with MIC values ranging between 0.39 μg/mL and 12.50 μg/mL; MFC values ranged between 3.12 μg/mL and 25.00 μg/mL; a significant anticandidal activity was noted (MIC values comprised between 0.39 μg/mL and 12.50 μg/mL). Although their low cytotoxic effect (CC50 ranged between 0.58 mg/mL and 12.00 mg/mL), the essential oils did not show antiviral activity against coxsakievirus B3. Conclusion The essential oils obtained from Hypericum triquetrifolium can be used as antimicrobial agents and could be safe at non cytotoxic doses. As shown for the tested essential oils, comparative analysis need to be undertaken to better characterize also the antimicrobial activities of Hypericum triquetrifolium extracts with different solvents as well as their purified fractions and their pure secondary metabolites. PMID:23360506

Synthesis and spectral characterization of 2-((2-hydroxybenzylidene)amino)-2-methylpropane-1,3-diol derived complexes: Molecular docking and antimicrobial studies

NASA Astrophysics Data System (ADS)

Ansari, Istikhar A.; Sama, Farasha; Raizada, Mukul; Shahid, M.; Rajpoot, Ravi Kant; Siddiqi, Zafar A.

2017-01-01

A series of four homo-dinuclear transition metal complexes with stoichiometry [M2(HL)2(H2O)2] [M = Fe (1), Co (2), Ni (3) and Cu (4); H3L = 2-((2-hydroxybenzylidene)amino)-2-methylpropane-1,3-diol] has been prepared. Ligand (H3L) was obtained by the condensation of 2-amino-2-methyl-1,3-propanediol (H2ampd) with salicylaldehyde. The complexes (1-4) are characterized employing elemental analysis, FTIR, ESI mass, 1H &13C NMR, EPR, UV Visible, TGA, cyclic voltammetry, and magnetic studies. Spectral data ascertained the bonding features and the geometry of the complexes and revealed that all the complexes adopt distorted octahedral geometry with high spin state of metal ions. Thermal and ESI mass data confirmed the proposed stoichiometry of the complexes. Cyclic voltammetric (CV) studies ascertain the formation of MII/MIII quasi-reversible redox couples in solution. The antimicrobial activities of the present complexes have been examined against few bacteria (E. coli, B. subtilis, S. aureus and S. typhymurium) and fungi (C. albicans, A. fumigatus and P. marneffeiin) suggesting that the present compounds show moderate to high antimicrobial properties. Among all the compounds tested, complex (4) exhibited highest antibacterial as well as antifungal activity. Molecular docking studies of the free ligand and the complexes are performed with BDNA.

Identification and characterization of novel multiple bacteriocins produced by Leuconostoc pseudomesenteroides QU 15.

PubMed

Sawa, N; Okamura, K; Zendo, T; Himeno, K; Nakayama, J; Sonomoto, K

2010-07-01

To characterize novel multiple bacteriocins produced by Leuconostoc pseudomesenteroides QU 15. Leuconostoc pseudomesenteroides QU 15 isolated from Nukadoko (rice bran bed) produced novel bacteriocins. By using three purification steps, four antimicrobial peptides termed leucocin A (ΔC7), leucocin A-QU 15, leucocin Q and leucocin N were purified from the culture supernatant. The amino acid sequences of leucocin A (ΔC7) and leucocin A-QU 15 were identical to that of leucocin A-UAL 187 belonging to class IIa bacteriocins, but leucocin A (ΔC7) was deficient in seven C-terminal residues. Leucocin Q and leucocin N are novel class IId bacteriocins. Moreover, the DNA sequences encoding three bacteriocins, leucocin A-QU 15, leucocin Q and leucocin N were obtained. These bacteriocins including two novel bacteriocins were identified from Leuc. pseudomesenteroides QU 15. They showed similar antimicrobial spectra, but their intensities differed. The C-terminal region of leucocin A-QU 15 was important for its antimicrobial activity. Leucocins Q and N were encoded by adjacent open reading frames (ORFs) in the same operon, but leucocin A-QU 15 was not. These leucocins were produced concomitantly by the same strain. Although the two novel bacteriocins were encoded by adjacent ORFs, a characteristic of class IIb bacteriocins, they did not show synergistic activity. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

Design and synthesis of positional isomers of 5 and 6-bromo-1-[(phenyl)sulfonyl]-2-[(4-nitrophenoxy)methyl]-1H-benzimidazoles as possible antimicrobial and antitubercular agents.

PubMed

Ranjith, P Karuvalam; Rajeesh, P; Haridas, Karickal R; Susanta, Nayak K; Row, Tayur N Guru; Rishikesan, R; Kumari, N Suchetha

2013-09-15

In this Letter, we report the structure-activity relationship (SAR) studies on series of positional isomers of 5(6)-bromo-1-[(phenyl)sulfonyl]-2-[(4-nitrophenoxy)methyl]-1H-benzimidazoles derivatives 7(a-j) and 8(a-j) synthesized in good yields and characterized by (1)H NMR, (13)C NMR and mass spectral analyses. The crystal structure of 7a was evidenced by X-ray diffraction study. The newly synthesized compounds were evaluated for their in vitro antibacterial activity against Staphylococcus aureus, (Gram-positive), Escherichia coli and Klebsiella pneumoniae (Gram-negative), antifungal activity against Candida albicans, Aspergillus flavus and Rhizopus sp. and antitubercular activity against Mycobacterium tuberculosis H37Rv, Mycobacterium smegmatis, Mycobacterium fortuitum and MDR-TB strains. The synthesized compounds displayed interesting antimicrobial activity. The compounds 7b, 7e and 7h displayed significant activity against Mycobacterium tuberculosis H37Rv strain. Copyright © 2013 Elsevier Ltd. All rights reserved.

GC and GC/MS Analysis of Essential Oil Composition of the Endemic Soqotraen Leucas virgata Balf.f. and Its Antimicrobial and Antioxidant Activities

PubMed Central

Mothana, Ramzi A.; Al-Said, Mansour S.; Al-Yahya, Mohammed A.; Al-Rehaily, Adnan J.; Khaled, Jamal M.

2013-01-01

Leucas virgata Balf.f. (Lamiaceae) was collected from the Island Soqotra (Yemen) and its essential oil was obtained by hydrodistillation. The chemical composition of the oil was investigated by GC and GC-MS. Moreover, the essential oil was evaluated for its antimicrobial activity against two Gram-positive bacteria, two Gram-negative bacteria, and one yeast species by using broth micro-dilution assay for minimum inhibitory concentrations (MIC) and antioxidant activity by measuring the scavenging activity of the DPPH radical. The investigation led to the identification of 43 constituents, representing 93.9% of the total oil. The essential oil of L. virgata was characterized by a high content of oxygenated monoterpenes (50.8%). Camphor (20.5%) exo-fenchol (3.4%), fenchon (5.4%), and borneol (3.1%) were identified as the main components. Oxygenated sesquiterpenes were found as the second major group of compounds (21.0%). β-Eudesmol (6.1%) and caryophyllene oxide (5.1%) were the major compounds among oxygenated sesquiterpenes. The results of the antimicrobial assay showed that the oil exhibited a great antibacterial activity against the tested S. aureus, B. subtilis, and E. coli. No activity was found against P. aeruginosa and C. albicans. Moreover, the DPPH-radical scavenging assay exhibited only a moderate antioxidant activity (31%) for the oil at the highest concentration tested (1 mg/mL). PMID:24284402

A new effective assay to detect antimicrobial activity of filamentous fungi.

PubMed

Pereira, Eric; Santos, Ana; Reis, Francisca; Tavares, Rui M; Baptista, Paula; Lino-Neto, Teresa; Almeida-Aguiar, Cristina

2013-01-15

The search for new antimicrobial compounds and the optimization of production methods turn the use of antimicrobial susceptibility tests a routine. The most frequently used methods are based on agar diffusion assays or on dilution in agar or broth. For filamentous fungi, the most common antimicrobial activity detection methods comprise the co-culture of two filamentous fungal strains or the use of fungal extracts to test against single-cell microorganisms. Here we report a rapid, effective and reproducible assay to detect fungal antimicrobial activity against single-cell microorganisms. This method allows an easy way of performing a fast antimicrobial screening of actively growing fungi directly against yeast. Because it makes use of an actively growing mycelium, this bioassay also provides a way for studying the production dynamics of antimicrobial compounds by filamentous fungi. The proposed assay is less time consuming and introduces the innovation of allowing the direct detection of fungal antimicrobial properties against single cell microorganisms without the prior isolation of the active substance(s). This is particularly useful when performing large screenings for fungal antimicrobial activity. With this bioassay, antimicrobial activity of Hypholoma fasciculare against yeast species was observed for the first time. Copyright © 2012 Elsevier GmbH. All rights reserved.

Antimicrobial particles from cationic lipid and polyelectrolytes.

PubMed

Melo, Letícia D; Mamizuka, Elsa M; Carmona-Ribeiro, Ana M

2010-07-20

Hybrid nanoparticles from cationic lipid and polymers were prepared and characterized regarding physical properties and antimicrobial activity. Carboxymethylcellulose (CMC) and polydiallyldimethylammonium chloride (PDDA) were sequentially added to cationic bilayer fragments (BF) prepared from ultrasonic dispersion in water of the synthetic and cationic lipid dioctadecyldimethylammonium bromide (DODAB). Particles thus obtained were characterized by dynamic light-scattering for determination of z-average diameter (Dz) and zeta-potential (zeta). Antimicrobial activity of the DODAB BF/CMC/PDDA particles against Pseudomonas aeruginosa or Staphylococcus aureus was determined by plating and CFU counting over a range of particle compositions. DODAB BF/CMC/PDDA particles exhibited sizes and zeta-potentials strictly dependent on DODAB, CMC, and PDDA concentrations. At 0.1 mM DODAB, 0.1 mg/mL CMC, and 0.1 mg/mL PDDA, small cationic particles with Dz = 100 nm and zeta = 30 mV were obtained. At 0.5 mM DODAB, 0.5 mg/mL CMC and 0.5 mg/mL PDDA, large cationic particles with Dz = 470 nm and zeta = 50 mV were obtained. Both particulates were highly reproducible regarding physical properties and yielded 0% of P. aeruginosa viability (10(7) CFU/mL) at 1 or 2 microg/mL PDDA dissolved in solution or in form of particles, respectively. 99% of S. aureus cells died at 10 microg/mL PDDA alone or in small or large DODAB BF/CMC/PDDA particles. The antimicrobial effect was dependent on the amount of positive charge on particles and independent of particle size. A high microbicide potency for PDDA over a range of nanomolar concentrations was disclosed. P. aeruginosa was more sensitive to all cationic assemblies than S. aureus.

Sonorensin: an Antimicrobial Peptide, Belonging to the Heterocycloanthracin Subfamily of Bacteriocins, from a New Marine Isolate, Bacillus sonorensis MT93

PubMed Central

Chopra, Lipsy; Singh, Gurdeep; Choudhary, Vikas

2014-01-01

Marine environments are the greatest fronts of biodiversity, representing a resource of unexploited or unknown microorganisms and new substances having potential applications. Among microbial products, antimicrobial peptides (AMPs) have received great attention recently due to their applications as food preservatives and therapeutic agents. A new marine soil isolate producing an AMP was identified as Bacillus sonorensis based on 16S rRNA gene sequence analysis. It produced an AMP that showed a broad spectrum of activity against both Gram-positive and Gram-negative bacteria. The peptide, named sonorensin, was purified to homogeneity using a combination of chromatographic techniques. The intact molecular mass of the purified peptide, 6,274 Da, as revealed by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF), was in agreement with Tricine-SDS-PAGE analysis. A PCR array of primers was used to identify AMP structural genes, which allowed the successful amplification of the related genes from strain MT93. The putative open reading frame of sonorensin was amplified, cloned into the pET-32a(+) vector, expressed as a thioredoxin (Trx) fusion protein in Escherichia coli, and then purified. Sequence alignment analysis revealed that the bacteriocin being reported could belong to new subfamily of bacteriocins, heterocycloanthracin. The peptide indicated its potential as a biocontrol agent or food antimicrobial agent, due to its antimicrobial activity against bacteria such as Listeria monocytogenes and Staphylococcus aureus. This is the first report of the production, purification, and characterization of wild-type and recombinant bacteriocin by B. sonorensis and the first bacteriocin of the heterocycloanthracin subfamily to be characterized. PMID:24610839

Sonorensin: an antimicrobial peptide, belonging to the heterocycloanthracin subfamily of bacteriocins, from a new marine isolate, Bacillus sonorensis MT93.

PubMed

Chopra, Lipsy; Singh, Gurdeep; Choudhary, Vikas; Sahoo, Debendra K

2014-05-01

Marine environments are the greatest fronts of biodiversity, representing a resource of unexploited or unknown microorganisms and new substances having potential applications. Among microbial products, antimicrobial peptides (AMPs) have received great attention recently due to their applications as food preservatives and therapeutic agents. A new marine soil isolate producing an AMP was identified as Bacillus sonorensis based on 16S rRNA gene sequence analysis. It produced an AMP that showed a broad spectrum of activity against both Gram-positive and Gram-negative bacteria. The peptide, named sonorensin, was purified to homogeneity using a combination of chromatographic techniques. The intact molecular mass of the purified peptide, 6,274 Da, as revealed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF), was in agreement with Tricine-SDS-PAGE analysis. A PCR array of primers was used to identify AMP structural genes, which allowed the successful amplification of the related genes from strain MT93. The putative open reading frame of sonorensin was amplified, cloned into the pET-32a(+) vector, expressed as a thioredoxin (Trx) fusion protein in Escherichia coli, and then purified. Sequence alignment analysis revealed that the bacteriocin being reported could belong to new subfamily of bacteriocins, heterocycloanthracin. The peptide indicated its potential as a biocontrol agent or food antimicrobial agent, due to its antimicrobial activity against bacteria such as Listeria monocytogenes and Staphylococcus aureus. This is the first report of the production, purification, and characterization of wild-type and recombinant bacteriocin by B. sonorensis and the first bacteriocin of the heterocycloanthracin subfamily to be characterized.

Antimicrobial/cytolytic peptides from the venom of the North African scorpion, Androctonus amoreuxi: biochemical and functional characterization of natural peptides and a single site-substituted analog.

PubMed

Almaaytah, Ammar; Zhou, Mei; Wang, Lei; Chen, Tianbao; Walker, Brian; Shaw, Chris

2012-06-01

The venoms of scorpions are complex cocktails of polypeptide toxins that fall into two structural categories: those that contain cysteinyl residues with associated disulfide bridges and those that do not. As the majority of lethal toxins acting upon ion channels fall into the first category, most research has been focused there. Here we report the identification and structural characterization of two novel 18-mer antimicrobial peptides from the venom of the North African scorpion, Androctonus amoreuxi. Named AamAP1 and AamAP2, both peptides are C-terminally amidated and differ in primary structure at just two sites: Leu-->Pro at position 2 and Phe-->Ile at position 17. Synthetic replicates of both peptides exhibited a broad-spectrum of antimicrobial activity against a Gram-positive bacterium (Staphylococcus aureus), a Gram-negative bacterium (Escherichia coli) and a yeast (Candida albicans), at concentrations ranging between 20 μM and 150 μM. In this concentration range, both peptides produced significant degrees of hemolysis. A synthetic replicate of AamAP1 containing a single substitution (His-->Lys) at position 8, generated a peptide (AamAP-S1) with enhanced antimicrobial potency (3-5 μM) against the three test organisms and within this concentration range, hemolytic effects were negligible. In addition, this His-->Lys variant exhibited potent growth inhibitory activity (ID(50) 25-40 μm) against several human cancer cell lines and endothelial cells that was absent in both natural peptides. Natural bioactive peptide libraries, such as those that occur in scorpion venoms, thus constitute a unique source of novel lead compounds with drug development potential whose biological properties can be readily manipulated by simple synthetic chemical means. Copyright © 2012 Elsevier Inc. All rights reserved.

Biosynthesis of silver and zinc oxide nanoparticles using Pichia fermentans JA2 and their antimicrobial property

NASA Astrophysics Data System (ADS)

Chauhan, Ritika; Reddy, Arpita; Abraham, Jayanthi

2015-01-01

The development of eco-friendly alternative to chemical synthesis of metal nanoparticles is of great challenge among researchers. The present study aimed to investigate the biological synthesis, characterization, antimicrobial study and synergistic effect of silver and zinc oxide nanoparticles against clinical pathogens using Pichia fermentans JA2. The extracellular biosynthesis of silver and zinc oxide nanoparticles was investigated using Pichia fermentans JA2 isolated from spoiled fruit pulp bought in Vellore local market. The crystalline and stable metallic nanoparticles were characterized evolving several analytical techniques including UV-visible spectrophotometer, X-ray diffraction pattern analysis and FE-scanning electron microscope with EDX-analysis. The biosynthesized metallic nanoparticles were tested for their antimicrobial property against medically important Gram positive, Gram negative and fungal pathogenic microorganisms. Furthermore, the biosynthesized nanoparticles were also evaluated for their increased antimicrobial activities with various commercially available antibiotics against clinical pathogens. The biosynthesized silver nanoparticles inhibited most of the Gram negative clinical pathogens, whereas zinc oxide nanoparticles were able to inhibit only Pseudomonas aeruginosa. The combined effect of standard antibiotic disc and biosynthesized metallic nanoparticles enhanced the inhibitory effect against clinical pathogens. The biological synthesis of silver and zinc oxide nanoparticles is a novel and cost-effective approach over harmful chemical synthesis techniques. The metallic nanoparticles synthesized using Pichia fermentans JA2 possess potent inhibitory effect that offers valuable contribution to pharmaceutical associations.

Intestinal Escherichia coli colonization in a mallard duck population over four consecutive winter seasons.

PubMed

Rödiger, Stefan; Kramer, Toni; Frömmel, Ulrike; Weinreich, Jörg; Roggenbuck, Dirk; Guenther, Sebastian; Schaufler, Katharina; Schröder, Christian; Schierack, Peter

2015-09-01

We report the population structure and dynamics of one Escherichia coli population of wild mallard ducks in their natural environment over four winter seasons, following the characterization of 100 isolates each consecutive season. Macro-restriction analysis was used to define isolates variously as multi- or 1-year pulsed-field gel electrophoresis (PFGE) types. Isolates were characterized genotypically based on virulence-associated genes (VAGs), phylogenetic markers, and phenotypically based on haemolytic activity, antimicrobial resistance, adhesion to epithelial cells, microcin production, motility and carbohydrate metabolism. Only 12 out of 220 PFGE types were detectable over more than one winter, and classified as multi-year PFGE types. There was a dramatic change of PFGE types within two winter seasons. Nevertheless, the genetic pool (VAGs) and antimicrobial resistance pattern remained remarkably stable. The high diversity and dynamics of this E. coli population were also demonstrated by the occurrence of PFGE subtypes and differences between isolates of one PFGE type (based on VAGs, antimicrobial resistance and adhesion rates). Multi- and 1-year PFGE types differed in antimicrobial resistance, VAGs and adhesion. Other parameters were not prominent colonization factors. In conclusion, the high diversity, dynamics and stable genetic pool of an E. coli population seem to enable their successful colonization of host animal population over time. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Biosynthesis, characterization, and antimicrobial applications of silver nanoparticles.

PubMed

Singh, Priyanka; Kim, Yeon Ju; Singh, Hina; Wang, Chao; Hwang, Kyu Hyon; Farh, Mohamed El-Agamy; Yang, Deok Chun

2015-01-01

In the present study, the strain Brevibacterium frigoritolerans DC2 was explored for the efficient and extracellular synthesis of silver nanoparticles. These biosynthesized silver nanoparticles were characterized by ultraviolet-visible spectrophotometry, which detected the formation of silver nanoparticles in the reaction mixture and showed a maximum absorbance at 420 nm. In addition, field emission transmission electron microscopy revealed the spherical shape of the nanoparticles. The dynamic light scattering results indicated the average particle size of the product was 97 nm with a 0.191 polydispersity index. Furthermore, the product was analyzed by energy dispersive X-ray spectroscopy, X-ray diffraction, and elemental mapping, which displayed the presence of elemental silver in the product. Moreover, on a medical platform, the product was checked against pathogenic microorganisms including Vibrio parahaemolyticus, Salmonella enterica, Bacillus anthracis, Bacillus cereus, Escherichia coli, and Candida albicans. The nanoparticles demonstrated antimicrobial activity against all of these pathogenic microorganisms. Additionally, the silver nanoparticles were evaluated for their combined effects with the commercial antibiotics lincomycin, oleandomycin, vancomycin, novobiocin, penicillin G, and rifampicin against these pathogenic microorganisms. These results indicated that the combination of antibiotics with biosynthesized silver nanoparticles enhanced the antimicrobial effects of antibiotics. Therefore, the current study is a demonstration of an efficient biological synthesis of silver nanoparticles by B. frigoritolerans DC2 and its effect on the enhancement of the antimicrobial efficacy of well-known commercial antibiotics.

Nickel(II) and palladium(II) triphenylphosphine complexes incorporating tridentate Schiff base ligands: Synthesis, characterization and biocidal activities

NASA Astrophysics Data System (ADS)

Shabbir, Muhammad; Akhter, Zareen; Ashraf, Ahmad Raza; Ismail, Hammad; Habib, Anum; Mirza, Bushra

2017-12-01

Nickel(II) and palladium(II) triphenylphosphine complexes incorporating tridentate Schiff bases have been prepared and characterized by elemental analysis as well as by spectroscopic techniques (FTIR & NMR). The synthesized compounds were assessed to check their potential biocidal activity by using different biological assays (brine shrimp cytotoxicity, antimicrobial, antioxidant, antitumor and drug-DNA interaction). Results of brine shrimp cytotoxicity assay showed that ligand molecules are more bioactive than metal complexes with LD50 as low as 12.4 μg/mL. The prominent antitumor activity was shown by nickel complexes while the palladium complexes exhibited moderate activity. The synthesized compounds have shown high propensity for DNA binding either through intercalation or groove binding which represents the mechanism of antitumor effect of these compounds. Additionally, ligand molecules and nickel metal complexes showed significant antioxidant activity with IC50 values as low as 3.1 μg/mL and 18.9 μg/mL respectively while palladium complexes exhibited moderate activity. Moreover, in antimicrobial assays H2L1, Ni(L1)PPh3 and H2L3 showed dual inhibition against bacterial and fungal strains while for the rest of the compounds varying degree of activity was recorded against different strains. Overall comparison of results suggests that the synthesized compounds can be promising candidate for drug formulation and development.

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

PubMed

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.

Purification, characterization and application of a novel antimicrobial peptide from Andrias davidianus blood.

PubMed

Pei, J; Feng, Z; Ren, T; Sun, H; Han, H; Jin, W; Dang, J; Tao, Y

2018-01-01

The Andrias davidianus has been known as a traditional Chinese medicine for a long time. Its blood is considered as a waste or by-product of the meat production industry. Although there are reports on isolation of the antimicrobial peptides from different resources, there are no reports of their isolation from A. davidianus blood. In this work, an antimicrobial peptide, andricin B, was isolated from the blood of A. davidianus by an innovative method in which the magnetic liposome adsorption was combined with reversed-phase high-performance liquid chromatography. The structure, antimicrobial activity and safety of andricin B were further investigated. Amino acid sequence was determined by N-terminal sequencing and found to be Gly-Leu-Thr-Arg-Leu-Phe-Ser-Val-Ile-Lys. Circular dichroism (CD) spectra and prediction of three-dimensional structure by bioinformatics software suggested the presence of a well-defined random coil conformation. Andricin B was found to be active against all bacteria tested in this study as well as some fungi. The minimum inhibitory concentrations (MICs) were in the range 8-64 μg ml -1 . Moreover, the haemolytic testing also suggested that andricin B could be considered safe at the MICs. Finally, andricin B was shown to inhibit the growth of Staphylococcus aureus in the cooked meat of A. davidianus. This study shows that andricin B is a promising novel antimicrobial peptide that may provide further insights towards the development of new drugs. This is the pioneer study on screening and isolation of antimicrobial peptide from the blood of Andrias davidianus. Here, we have developed a novel method by combining magnetic liposomes adsorption with reversed-phase high-performance liquid chromatography to purify and screen the antimicrobial peptides. From this screen, we identified a novel antimicrobial peptide which we name as andricin B. Andricin B is unique as it checks the growth of both Gram-positive and Gram-negative bacteria as well as few fungal species. © 2017 The Society for Applied Microbiology.

The in vitro Antimicrobial Activity and Chemometric Modelling of 59 Commercial Essential Oils against Pathogens of Dermatological Relevance.

PubMed

Orchard, Ané; Sandasi, Maxleene; Kamatou, Guy; Viljoen, Alvaro; van Vuuren, Sandy

2017-01-01

This study reports on the inhibitory concentration of 59 commercial essential oils recommended for dermatological conditions, and identifies putative compounds responsible for antimicrobial activity. Essential oils were investigated for antimicrobial activity using minimum inhibitory concentration assays. Ten essential oils were identified as having superior antimicrobial activity. The essential oil compositions were determined using gas chromatography coupled to mass spectrometry and the data analysed with the antimicrobial activity using multivariate tools. Orthogonal projections to latent structures models were created for seven of the pathogens. Eugenol was identified as the main biomarker responsible for antimicrobial activity in the majority of the essential oils. The essential oils mostly displayed noteworthy antimicrobial activity, with five oils displaying broad-spectrum activity against the 13 tested micro-organisms. The antimicrobial efficacies of the essential oils highlight their potential in treating dermatological infections and through chemometric modelling, bioactive volatiles have been identified. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Silver nanoparticles: green synthesis using Phoenix dactylifera fruit extract, characterization, and anti-oxidant and anti-microbial activities

NASA Astrophysics Data System (ADS)

Shaikh, Anas Ejaz; Satardekar, Kshitij Vasant; Khan, Rummana Rehman; Tarte, Nanda Amit; Barve, Siddhivinayak Satyasandha

2018-03-01

Hydro-alcoholic (2:8 v/v) extract of the pulp of Phoenix dactylifera fruit pulp obtained using Soxhlet extraction (70 °C, 6 h) was found to contain alkaloids, sterols, tannins, flavonoids, cardiac glycosides, proteins, and carbohydrates. An aqueous solution (20% v/v) of the extract led to the synthesis of silver nanoparticles (AgNPs) from 0.01 M AgNO3 solution as confirmed by the surface plasmon resonance at 445 nm determined using UV-visible spectroscopy after 24 h. The synthesized AgNPs were found to be mostly spherical and complexed with phytochemicals from the extract. The size of AgNPs ranged from 12.2-140.2 nm with mean diameter of 47.0 nm as characterized by scanning electron microscopy (SEM). The elemental composition of the AgNPs complexed with the phytochemicals was found to be 80.49% silver (Ag), 15.21% carbon (C), and 4.30% oxygen (O) on a weight basis by energy-dispersive spectroscopy (EDS). Using the α,α-diphenyl-β-picrylhydrazyl (DPPH) assay, an anti-oxidant activity of 89.15% for 1 µg L-1 ultrasonically homogenized ethanolic solution of complexed AgNPs was obtained (equivalent to 0.20 mg mL-1 gallic acid solution), while methanolic solution of plant extract possessed an EC50 value of 3.45% (v/v) (equivalent to 0.11 mg mL-1 gallic acid solution). The plant-nanosilver broth was also found to possess effective anti-microbial activity against Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 6538, and Candida albicans ATCC 10231 as assessed by the disc diffusion assay. However, the plant extract showed negligible anti-microbial activity.

Rational design of antimicrobial C3a analogues with enhanced effects against Staphylococci using an integrated structure and function-based approach.

PubMed

Pasupuleti, Mukesh; Walse, Björn; Svensson, Bo; Malmsten, Martin; Schmidtchen, Artur

2008-09-02

The anaphylatoxin C3a and its inactivated derivative C3adesArg, generated during complement activation, exert direct antimicrobial effects, mediated via its C-terminal region [Nordahl et al. (2004) Proc. Natl. Acad. Sci. U.S.A. 101, 16879-16884]. During evolution, this region of C3a displays subtle changes in net charge, while preserving a moderate but variable amphipathicity [Pasupuleti et al. (2007) J. Biol. Chem. 282, 2520-2528]. In this study, we mimic these evolutionary changes, employing a design approach utilizing selected amino acid substitutions at strategic and structurally relevant positions in the original human C3a peptide CNYITELRRQHARASHLGLA, followed by structure-activity studies incorporating sequence-dependent QSAR models as tools for generation of C3a peptide variants with enhanced effects. While the native peptide and related amphipathic analogues of moderate positive net charge were active against the Gram-negative Escherichia coli, activity against the Gram-positive Staphylococcus aureus was primarily observed for peptides characterized by a combination of a relatively high net charge (+6-7) and a propensity to adopt an alpha-helical conformation with amphipathic character. Such increased helicity and charge also conferred activity against the fungus Candida albicans. A central histidine residue (H11), evolutionarily conserved among vertebrates, conferred high selectivity toward microbes, while substitutions with leucine rendered the peptides hemolytic. Selected C3a analogues retained their specificity against staphylococci in the presence of human plasma, while showing low cytotoxicity. The work illustrates structure-activity relationships underlying the function and specificity of antimicrobial C3a and related analogues and provides insights into the forces that drive evolution of antimicrobial peptides.

Development and characterization of carrageenan/grapefruit seed extract composite films for active packaging.

PubMed

Kanmani, Paulraj; Rhim, Jong-Whan

2014-07-01

Carrageenan-based antimicrobial films were developed by incorporation of grape fruit seed extract (GSE) at different concentration into the polymer using a solvent casing method and their physical, mechanical, and antimicrobial properties were examined. The carrageenan/GSE composite films appeared yellowish tint due to the polyphenolic compounds in the GSE. SEM analysis showed rough surface with sponge like structures on the cross section of the films. FT-IR results indicated at GSE had good compatibility with carrageenan. The amorphous structure of polymer films was not changed by the incorporation of GSE. But, the addition of GSE increased moisture content, water vapor permeability, and surface hydrophilicity of the films. The tensile strength and elastic modulus decreased with increasing content of GSE, however, the elongation at break increased significantly up to 6.6μg/mL of GSE then decreased thereafter. Thermal stability of the films was not influenced by GSE incorporation. The carrageenan/GSE composite films exhibited great antibacterial activity against food borne pathogens. These results suggest that the carrageenan-based composite films have a high potential for being used as an antimicrobial or active food packaging applications. Copyright © 2014 Elsevier B.V. All rights reserved.

Polyketide family of novel antibacterial 7-O-methyl-5'-hydroxy-3'-heptenoate-macrolactin from seaweed-associated Bacillus subtilis MTCC 10403.

PubMed

Chakraborty, Kajal; Thilakan, Bini; Raola, Vamshi Krishna

2014-12-17

Seaweed-associated heterotrophic bacterial communities were screened to isolate potentially useful antimicrobial strains, which were characterized by phylogenetic analysis. The bacteria were screened for the presence of metabolite genes involved in natural product biosynthetic pathway, and the structural properties of secondary metabolites were correlated with the genes. Bioactivity-guided isolation of polyene antibiotic 7-O-methyl-5'-hydroxy-3'-heptenoate-macrolactin from Bacillus subtilis MTCC10403 associated with seaweed Anthophycus longifolius using mass spectrometry and extensive 2D-NMR studies was carried out. The newly isolated macrolactin compound is a bactericidal antibiotic with broad spectrum activity against human opportunistic clinical pathogens. The biosynthetic pathway of 7-O-methyl-5'-hydroxy-3'-heptenoate-macrolactin by means of a stepwise, decarboxylative condensation pathway established the PKS-assisted biosynthesis of the parent macrolactin and the side-chain 5-hydroxyhept-3-enoate moiety attached to the macrolactin ring system at C-7. Antimicrobial activity analysis combined with the results of amplifying genes encoding for polyketide synthetase and nonribosomal peptide synthetase showed that seaweed-associated bacteria had broad-spectrum antimicrobial activity. The present work may have an impact on the exploitation of macrolactins for pharmaceutical and biotechnological applications.

Innovative material containing the natural product curcumin, with enhanced antimicrobial properties for active packaging.

PubMed

Papadimitriou, A; Ketikidis, I; Stathopoulou, M-E K; Banti, C N; Papachristodoulou, C; Zoumpoulakis, L; Agathopoulos, S; Vagenas, G V; Hadjikakou, S K

2018-03-01

Curcumin (Curc) reacts with zinc di‑iodine (ZnI 2 ) in 2:1molar ratio in the presence of an excess of a base triethylamine ((CH 3 CH 2 ) 3 N) in methanol (CH 3 OH) solution towards the amorphous solid material of formula [ZnI 2 (Curc) 2 ] (1). The complex was characterized by melting point (m.p.), Fourier Transform-Infra Red (FT-IR) and Nuclear Magnetic Resonance of hydrogen nucleus ( 1 H NMR) spectroscopy. The formula of 1 was determined by X-ray fluorescence (XRF) analysis. The retention of the structure in solution was confirmed by 1 H NMR spectroscopy. The antimicrobial activity of the complex has been studied against the bacteria Pseudomonas aeruginosa (PAO1). The Minimum Inhibitory Concentrations (MIC) of the compounds 1 and Curc against P. aeruginosa (PAO1) are: 71.3μΜ (75.3μg/mL) for [ZnI 2 (Curc) 2 ] and 339μM (125μg/mL) for Curc, respectively. Moreover, the antimicrobial activity of the new material which was diffused in polystyrene against biofilm formed by PAO1 was also calculated. Copyright © 2017 Elsevier B.V. All rights reserved.

Preparation of Chloramphenicol/Amino Acid Combinations Exhibiting Enhanced Dissolution Rates and Reduced Drug-Induced Oxidative Stress.

PubMed

Sterren, Vanesa B; Aiassa, Virginia; Garnero, Claudia; Linck, Yamila Garro; Chattah, Ana K; Monti, Gustavo A; Longhi, Marcela R; Zoppi, Ariana

2017-11-01

Chloramphenicol is an old antibiotic agent that is re-emerging as a valuable alternative for the treatment of multidrug-resistant pathogens. However, it exhibits suboptimal biopharmaceutical properties and toxicity profiles. In this work, chloramphenicol was combined with essential amino acids (arginine, cysteine, glycine, and leucine) with the aim of improving its dissolution rate and reduce its toxicity towards leukocytes. The chloramphenicol/amino acid solid samples were prepared by freeze-drying method and characterized in the solid state by using Fourier transform infrared spectroscopy, powder X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and solid-state nuclear magnetic resonance. The dissolution properties, antimicrobial activity, reactive oxygen species production, and stability of the different samples were studied. The dissolution rate of all combinations was significantly increased in comparison to that of the pure active pharmaceutical ingredient. Additionally, oxidative stress production in human leukocytes caused by chloramphenicol was decreased in the chloramphenicol/amino acid combinations, while the antimicrobial activity of the antibiotic was maintained. The CAP:Leu binary combination resulted in the most outstanding solid system makes it suitable candidate for the development of pharmaceutical formulations of this antimicrobial agent with an improved safety profile.

Studies on electrochemical glucose sensing, antimicrobial activity and cytotoxicity of fabricated copper nanoparticle immobilized chitin nanostructure.

PubMed

Solairaj, Dhanasekaran; Rameshthangam, Palanivel; Muthukumaran, Palanisamy; Wilson, Jeyaraj

2017-08-01

In this study, copper nanoparticle immobilized chitin nanocomposite (CNP/CuNP) was synthesized and used for the development of non-enzymatic electrochemical sensor. The CNP/CuNP was characterized by X-ray diffraction (XRD), fourier transform infra red (FTIR) spectroscopy and high resolution transmission electron microscopy (HRTEM) analysis. The glucose sensing property of CNP/CuNP was investigated by cyclic voltammetry (CV) and chronoamperometry (CA). As a result of the synergistic effect of CNP and CuNP, the modified electrode displayed effective electro-oxidation of glucose in 0.1M NaOH solution. At 0.45V potential the modified electrode showed response towards glucose in the linear range of 1-1000μM with a lowest detection limit of 0.776μM with better selectivity and stability. In addition, the antimicrobial activity of CNP/CuNP was evaluated against bacterial and fungal strains. CNP/CuNP displayed enhanced antimicrobial activity when compared to CNP and CuNP alone. Similarly, cytotoxicity of CNP/CuNP was tested against Artemia salina, which showed no toxic effect in the tested concentration. Copyright © 2017 Elsevier B.V. All rights reserved.

In-vitro bio-fabrication of silver nanoparticle using Adhathoda vasica leaf extract and its anti-microbial activity

NASA Astrophysics Data System (ADS)

Nazeruddin, G. M.; Prasad, N. R.; Prasad, S. R.; Garadkar, K. M.; Nayak, Arpan Kumar

2014-07-01

It is well known that on treating the metallic salt solution with some plant extracts, a rapid reduction occurs leading to the formation of highly stable metal nanoparticles. Extracellular synthesis of metal nanoparticles using extracts of plants like Azadirachta indica (Neem), and Zingiber officinale (Ginger) has been reported to be successfully carried out. In this study we have developed a novel method to synthesize silver nanoparticles by mixing silver salt solution with leaf extract of Adhathoda vasica (Adulsa) without using any surfactant or external energy. By this method physiologically stable, bio-compatible Ag nanoparticles were formed which could be used for a variety of applications such as targeted drug delivery which ensures enhanced therapeutic efficacy and minimal side effects. With this method rapid synthesis of nanoparticles was observed to occur; i.e. reaction time was 1-2 h as compared to 2-4 days required by microorganisms. These nanoparticles were analyzed by various characterization techniques to reveal their morphology, chemical composition, and antimicrobial activity. TEM image of these NPs indicated the formation of spherical, non-uniform, poly-dispersed nanoparticles. A detailed study of anti-microbial activity of nanoparticles was carried out.

Synthesis, characterization, spectrophotometric, structural and antimicrobial studies of the newly charge transfer complex of p-phenylenediamine with π acceptor picric acid

NASA Astrophysics Data System (ADS)

Khan, Ishaat M.; Ahmad, Afaq; Oves, M.

2010-12-01

Charge transfer complex (CTC) of donor, p-phenylenediamine (PPD) and acceptor, 2,4,6-trinitrophenol (picric acid) has been studied in methanol at room temperature. The CT complex was synthesized and characterized by elemental analysis, FTIR spectra, 1H NMR spectroscopy and electronic absorption spectra which indicate the CT interaction associated with proton migration from the acceptor to the donor followed by hydrogen bonding via N +-H⋯O -. The thermal stability of CT complex was studied using TGA and DTA analyses techniques. The CT complex was screened for its antifungal activity against Aspergillus niger (Laboratory isolate), Candida albicans (IQA-109) and Penicillium sp. (Laboratory isolate) and antibacterial activity against two Gram-positive bacteria Staphylococcus aureus (MSSA 22) and Bacillus subtilis (ATCC 6051) and two Gram-negative bacteria Escherichia coli (K 12) and Pseudomonas aeruginosa (MTCC 2488). It gives good antimicrobial activity. The stoichiometry of the CT complex was found to be 1:1. The physical parameters of CT complex were evaluated by the Benesi-Hildebrand equation. On the basis of the studies, the structure of CT complex is [(PPDH) +(PA) -], and a general mechanism for its formation is proposed.

Antibody-directed targeting of lysostaphin adsorbed onto polylactide nanoparticles increases its antimicrobial activity against S. aureus in vitro

NASA Astrophysics Data System (ADS)

Satishkumar, R.; Vertegel, A. A.

2011-12-01

The objective of this paper was to study the effect of antibody-directed targeting of S. aureus by comparing the activities of lysostaphin conjugated to biodegradable polylactide nanoparticles (NPs) in the presence and in the absence of co-immobilized anti-S. aureus antibody. Lysostaphin-antibody-NP conjugates were synthesized through physical adsorption at different enzyme:antibody:NP ratios. The synthesized enzyme-NP conjugates were characterized by means of dynamic light scattering and zeta potential analysis, and the total protein binding yield on the NPs was characterized using Alexa Fluor 350 and 594 dyes for the S. aureus antibody and lysostaphin respectively. We observed enhanced antimicrobial activity for both enzyme-coated and enzyme-antibody-coated NPs for lysostaphin coatings corresponding to ~ 40% of the initial monolayer and higher compared to the free enzyme case (p < 0.05). At the highest antibody coating concentration, bacterial lysis rates for antibody-coated samples were significantly higher than for lysostaphin-coated samples lacking the antibody (p < 0.05). Such enzyme-NP conjugates thus have the potential for becoming novel therapeutic agents for treating antibiotic-resistant S. aureus infections.

Synthesis, characterization and biological activity of some platinum(II) complexes with Schiff bases derived from salicylaldehyde, 2-furaldehyde and phenylenediamine.

PubMed

Gaballa, Akmal S; Asker, Mohsen S; Barakat, Atiat S; Teleb, Said M

2007-05-01

Four platinum(II) complexes of Schiff bases derived from salicylaldehyde and 2-furaldehyde with o- and p-phenylenediamine were reported and characterized based on their elemental analyses, IR and UV-vis spectroscopy and thermal analyses (TGA). The complexes were found to have the general formula [Pt(L)(H(2)O)(2)]Cl(2) x nH(2)O (where n=0 for complexes 1, 3, 4; n=1 for complex 2. The data obtained show that Schiff bases were interacted with Pt(II) ions in the neutral form as a bidentate ligand and the oxygens rather than the nitrogens are the most probable coordination sites. Square planar geometrical structure with two coordinated water molecules were proposed for all complexes The free ligands, and their metal complexes were screened for their antimicrobial activities against the following bacterial species: E. coli, B. subtilis, P. aereuguinosa, S. aureus; fungus A. niger, A. fluves; and the yeasts C. albican, S. cervisiea. The activity data show that the platinum(II) complexes are more potent antimicrobials than the parent Schiff base ligands against one or more microorganisms.

Effect of chitosan addition to characteristic and antimicrobial activity of zinc doped hydroxyapatite

NASA Astrophysics Data System (ADS)

Rasyida, A.; Wicaksono, S. T.; Pradita, N. N.; Ardhyananta, H.; Purnomo, A.

2017-07-01

Hydroxyapatite (HAp) doping with zinc was prepared using sol gel method; different chitosan content were further added to prepare the composite, namely 10, 15 and 20% wt. The samples were characterized using FTIR, XRD, SEM-EDX, and AAS. In vitro antimicrobial activities of the composite were evaluated against gram positive and negative bacteria. FTIR results revealed that there were no important changes in the structure of composite, while 10% wt of chitosan in composite shows the highest inhibition zone against Escherichia coli after 24 h incubation. In addition, after 7 days of immersion in simulated body fluid, there were apatite formations in the surface of the composite. These might indicate that this composite could be used as a material candidate for bone substitute applications.

Controlled green synthesis of silver nanoparticles by Allium cepa and Musa acuminata with strong antimicrobial activity

NASA Astrophysics Data System (ADS)

Sahni, Geetika; Panwar, Amit; Kaur, Balpreet

2015-02-01

A controlled "green synthesis" approach to synthesize silver nanoparticles by Allium cepa and Musa acuminata plant extract has been reported. The effect of different process parameters, such as pH, temperature and time, on synthesis of Ag nanoparticles from plant extracts has been highlighted. The work reports an easy approach to control the kinetics of interaction of metal ions with reducing agents, stabilized by ammonia to achieve sub-10 nm particles with narrow size distribution. The nanoparticles have been characterized by UV-Visible spectra and TEM analysis. Excellent antimicrobial activity at extremely low concentration of the nanoparticles was observed against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Fusarium oxysporum which may allow their exploitation as a new generation nanoproduct in biomedical and agricultural applications.

Synthesis of monodispersed silver nanoparticles using Hibiscus cannabinus leaf extract and its antimicrobial activity

NASA Astrophysics Data System (ADS)

Bindhu, M. R.; Umadevi, M.

2013-01-01

Synthesis of silver nanoparticles using leaf extract of Hibiscus cannabinus has been investigated. The influences of different concentration of H. cannabinus leaf extract, different metal ion concentration and different reaction time on the above cases on the synthesis of nanoparticles were evaluated. The synthesized nanoparticles were characterized using UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). The prepared silver nanoparticles were monodispersed, spherical in shape with the average particle size of 9 nm and shows surface plasmon peak at 446 nm. The study also reveals that the ascorbic acid present in H. cannabinus leaf extract has been used as reducing agent. The prepared silver nanoparticle shows good antimicrobial activity against Escherichia coli, Proteus mirabilis and Shigella flexneri.

Antimicrobial, antiadhesive and antibiofilm activity of an ethanolic, anthocyanin-rich blueberry extract purified by solid phase extraction.

PubMed

Silva, S; Costa, E M; Mendes, M; Morais, R M; Calhau, C; Pintado, M M

2016-09-01

The present work aimed to characterize the impact of an anthocyanin-rich blueberry extract upon the growth, adhesion and biofilm formation of several pathogens including some multiresistant bacteria. A group comprised of reference strains and clinical multiresistant isolates of Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis, Acinetobacter baumannii and Staphylococcus aureus, were used to screen for antimicrobial activity. Microbial growth was determined through the measurement of the optical density while adhesion and biofilm formation was determined using the standard crystal violet staining procedure. The results showed that, while blueberry extract was only effective in hindering the growth of Staph. aureus and E. coli, it was capable of significantly inhibiting biofilm formation and bacterial adhesion for all micro-organisms tested. The extract demonstrated a considerable potential as a natural, alternative antimicrobial capable of either interfering with microbial growth or hamper the adhesion to surfaces, with Staph. aureus proving to be the most susceptible micro-organism. The overall study demonstrates the potential of anthocyanin extracts as natural effective alternative antimicrobial agents. Additionally, the extract's capacity to reduce adhesion without reducing bacterial growth reduces the likeliness of resistance development while reducing the probability of infection. © 2016 The Society for Applied Microbiology.

Culturable bacterial communities associated to Brazilian Oscarella species (Porifera: Homoscleromorpha) and their antagonistic interactions.

PubMed

Laport, Marinella Silva; Bauwens, Mathieu; de Oliveira Nunes, Suzanne; Willenz, Philippe; George, Isabelle; Muricy, Guilherme

2017-04-01

Sponges offer an excellent model to investigate invertebrate-microorganism interactions. Furthermore, bacteria associated with marine sponges represent a rich source of bioactive metabolites. The aim of this study was to characterize the bacteria inhabiting a genus of sponges, Oscarella, and their potentiality for antimicrobial production. Bacterial isolates were recovered from different Oscarella specimens, among which 337 were phylogenetically identified. The culturable community was dominated by Proteobacteria and Firmicutes, and Vibrio was the most frequently isolated genus, followed by Shewanella. When tested for antimicrobial production, bacteria of the 12 genera isolated were capable of producing antimicrobial substances. The majority of strains were involved in antagonistic interactions and inhibitory activities were also observed against bacteria of medical importance. It was more pronounced in some isolated genera (Acinetobacter, Bacillus, Photobacterium, Shewanella and Vibrio). These findings suggest that chemical antagonism could play a significant role in shaping bacterial communities within Oscarella, a genus classified as low-microbial abundance sponge. Moreover, the identified strains may contribute to the search for new sources of antimicrobial substances, an important strategy for developing therapies to treat infections caused by multidrug-resistant bacteria. This study was the first to investigate the diversity and antagonistic activity of bacteria isolated from Oscarella spp. It highlights the biotechnological potential of sponge-associated bacteria.

Microalgae associated Brevundimonas sp. MSK 4 as the nano particle synthesizing unit to produce antimicrobial silver nanoparticles.

PubMed

Rajamanickam, Karthic; Sudha, S S; Francis, Mebin; Sowmya, T; Rengaramanujam, J; Sivalingam, Periyasamy; Prabakar, Kandasamy

2013-09-01

The biosynthesis of silver nanoparticles and its antimicrobial property was studied using bacteria isolated from Spirulina products. Isolated bacteria were identified as Bacillus sp. MSK 1 (JX495945), Staphylococcus sp. MSK 2 (JX495946), Bacillus sp. MSK 3 (JX495947) and Brevundimonas sp. MSK 4 (JX495948). Silver nanoparticles (AgNPs) were synthesized using bacterial culture filtrate with AgNO3. The initial syntheses of Ag nanoparticles were characterized by UV-vis spectrophotometer (by measuring the color change to intense brown). Fourier Transform Infrared Spectroscopy (FTIR) study showed evidence that proteins are possible reducing agents and Energy-dispersive X-ray (EDX) study showing the metal silver as major signal. The structure of AgNPs was determined by Scanning electron microscopy (SEM) and X-ray diffraction (XRD). Synthesized Ag nanoparticles with an average size of 40-65 nm have antimicrobial property against human pathogens like Proteus vulgaris, Salmonella typhi, Vibrio cholera, Streptococcus sp., Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. Among the isolates Brevundimonas sp. MSK 4 alone showed good activity in both synthesis of AgNPs and antimicrobial activity. This work demonstrates the possible use of biological synthesized silver nanoparticles to combat the drug resistant problem. Copyright © 2013 Elsevier B.V. All rights reserved.

Production and characterization of curcumin microcrystals and evaluation of the antimicrobial and sensory aspects in minimally processed carrots.

PubMed

Silva, Anderson Clayton da; Santos, Priscila Dayane de Freitas; Palazzi, Nicole Campezato; Leimann, Fernanda Vitória; Fuchs, Renata Hernandez Barros; Bracht, Lívia; Gonçalves, Odinei Hess

2017-05-24

Nontoxic conserving agents are in demand by the food industry due to consumers concern about synthetic conservatives, especially in minimally processed food. The antimicrobial activity of curcumin, a natural phenolic compound, has been extensively investigated but hydrophobicity is an issue when applying curcumin to foodstuff. The objective of this work was to evaluate curcumin microcrystals as an antimicrobial agent in minimally processed carrots. The antimicrobial activity of curcumin microcrystals was evaluated in vitro against Gram-positive (Bacillus cereus and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) microorganisms, showing a statistically significant (p < 0.05) decrease in the minimum inhibitory concentration compared to in natura, pristine curcumin. Curcumin microcrystals were effective in inhibiting psychrotrophic and mesophile microorganisms in minimally processed carrots. Sensory analyses were carried out showing no significant difference (p < 0.05) between curcumin microcrystal-treated carrots and non-treated carrots in triangular and tetrahedral discriminative tests. Sensory tests also showed that curcumin microcrystals could be added as a natural preservative in minimally processed carrots without causing noticeable differences that could be detected by the consumer. One may conclude that the analyses of the minimally processed carrots demonstrated that curcumin microcrystals are a suitable natural compound to inhibit the natural microbiota of carrots from a statistical point of view.

Antimicrobial activities of secondary metabolites and phylogenetic study of sponge endosymbiotic bacteria, Bacillus sp. at Agatti Island, Lakshadweep Archipelago.

PubMed

Mohan, Gopi; Thipparamalai Thangappanpillai, Ajith Kumar; Ramasamy, Balagurunathan

2016-09-01

Twenty-one species of sponges were recorded under the class of Demospongiae and Calcareous sponges of which 19 species were new to Agatti reef. A total of 113 Sponge endosymbiotic bacterial strains were isolated from twenty-one species of sponges and screened for antimicrobial activity. Five bacterial strains of sponge endosymbiotic bacteria (SEB) namely SEB32, SEB33, SEB36, SEB43 and SEB51 showed antimicrobial activity against virulent marine fish pathogens such as Vibrio alginolyticus , Vibrio vulnificus , Vibrio parahaemolyticus , Aeromonas salmonicida , Flavobacterium sp., Edwardsiella sp., Proteus mirabilis and Citrobacter brackii . The secondary metabolites produced by SEB32 from sponge Dysidea fragilis (Montagu, 1818) [48] was selected with broad range of antibacterial activity and subjected for production, characterization by series of chromatography techniques and spectroscopic methods. Based on the results of FT-IR and mass spectrometry, the active molecule was tentatively predicted as "Pyrrol" and the structure is Pyrrolo[1,2 -a ]pyrazine-1,4-dione, hexahydro- with molecular formula of C7H10N2O2. The LC 50 of active molecule was 31 μg/ml and molecular weight of the metabolites was 154. The potential strain SEB32 was identified by gene sequence (GenBank Accession number JX985748) and identified as Bacillus sp. from GenBank database.

Expression of plectasin in Pichia pastoris and its characterization as a new antimicrobial peptide against Staphyloccocus and Streptococcus.

PubMed

Zhang, Jun; Yang, Yalin; Teng, Da; Tian, Zigang; Wang, Shaoran; Wang, Jianhua

2011-08-01

Recombinant plectasin, the first fungus defensin, was expressed in Pichia pastoris and purified, and its physical, chemical and antimicrobial characteristics were studied. Following a 120 h induction of recombinant yeast, the amount of total secreted protein reached 748.63 μg/ml. The percentage of recombinant plectasin was estimated to be 71.79% of the total protein. After purification with a Sephadex G-25 column and RP-HPLC, the identity of plectasin was verified by MALDI-TOF MS. Plectasin exhibited strong antimicrobial activity against the Gram-positive bacteria Staphyloccocusaureus, Staphylococcus epidermidis, Streptococcus pneumoniae, and Streptococcus suis. At a concentration of 2560 μg/ml, this peptide showed approximately equal activity against S. aureus, S. epidermidis, S. suis, and S. pneumoniae, when compared to 320 μg/ml vancomycin, 640 μg/ml penicillin, 320 μg/ml vancomycin and 160 μg/ml vancomycin, respectively. In addition, plectasin showed anti-S. aureus activity over a wide pH range of 2.0 and 10.0, a high thermal stability at 100 °C for 1h and remarkable resistance to papain and pepsin. The expression and characterization of recombinant plectasin in P. pastoris has potential to treat Streptococcus and Staphyloccocus infections when most traditional antibiotics show no effect on them. Our results indicate that plectasin can be produced in large quantities, and that it has pharmaceutical importance for the prevention and clinical treatment of Staphyloccocus and Streptococcus infections. Copyright © 2011 Elsevier Inc. All rights reserved.

Synthesis, characterization, and antimicrobial activity of silver(I) and copper(II) complexes of phosphate derivatives of pyridine and benzimidazole.

PubMed

Kalinowska-Lis, Urszula; Szewczyk, Eligia M; Chęcińska, Lilianna; Wojciechowski, Jakub M; Wolf, Wojciech M; Ochocki, Justyn

2014-01-01

Two silver(I) complexes--[Ag(4-pmOpe)]NO₃}(n) and [Ag(2-bimOpe)₂]NO₃--and three copper(II) complexes--[Cu₄Cl₆O(2-bimOpe)₄], [CuCl₂(4-pmOpe)₂], and [CuCl₂(2-bis(pm)Ope]--were synthesized by reaction of silver(I) nitrate or copper(II) chloride with phosphate derivatives of pyridine and benzimidazole, namely diethyl (pyridin-4-ylmethyl)phosphate (4-pmOpe), 1H-benzimidazol-2-ylmethyl diethyl phosphate (2-bimOpe), and ethyl bis(pyridin-2-ylmethyl)phosphate (2-bis(pm)Ope). These compounds were characterized by ¹H, ¹³C, and ³¹P NMR as well as IR spectroscopy, elemental analysis, and ESIMS spectrometry. Additionally, molecular and crystal structures of {[Ag(4-pmOpe)]NO₃}n and [Cu₄Cl₆O(2-bimOpe)₄] were determined by single-crystal X-ray diffraction analysis. The antimicrobial profiles of synthesized complexes and free ligands against test organisms from the ATCC and clinical sources were determined. Silver(I) complexes showed good antimicrobial activities against Candida albicans strains (MIC values of ∼19 μM). [Ag(2-bimOpe)₂]NO₃ was particularly active against Pseudomonas aeruginosa and methicillin-resistant Staphylococcus epidermidis, with MIC values of ∼5 and ∼10 μM, respectively. Neither copper(II) complexes nor the free ligands inhibited the growth of test organisms at concentrations below 500 μg mL⁻¹. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and antimicrobial evaluation of L-phenylalanine-derived C5-substituted rhodanine and chalcone derivatives containing thiobarbituric acid or 2-thioxo-4-thiazolidinone.

PubMed

Jin, Xin; Zheng, Chang-Ji; Song, Ming-Xia; Wu, Yan; Sun, Liang-Peng; Li, Yin-Jing; Yu, Li-Jun; Piao, Hu-Ri

2012-10-01

Four novel series of compounds, including the l-phenylalanine-derived C5-substituted rhodanine (6a-q, 7a-j) and chalcone derivatives containing thiobarbituric acid or 2-thioxo-4-thiazolidinone (9a-e, 11a-e) have been designed, synthesized, characterized, and evaluated for their antibacterial activity. Some of these compounds showed significant antibacterial activity against Gram-positive bacterias, especially against the strains of multidrug-resistant clinical isolates, among which compounds 6c-e, 6g, 6i, 6j and 6q exhibiting high levels of antimicrobial activity against Staphylococcus aureus RN4220 with minimum inhibitory concentration (MIC) values of 2 μg/mL. Compound 6q showed the most potent activity of all of the compounds against all of the test multidrug-resistant clinical isolates tested. Unfortunately, however, none of the compounds were active against Gram-negative bacteria at 64 μg/mL. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

New antibacterial germacrene from Verbesina negrensis.

PubMed

Mora, Flor D; Alpan, Lara; de Tommasi, Nunziatina; McCracken, Vance J; Nieto, Marcelo

2013-05-01

Several health benefits have been attributed to members of the Verbesina genus, including promotion of urinary and gastrointestinal health. Verbesina species are also reported to exhibit antibacterial, antiparasitic, and antioxidant activities. Although members of the Verbesina genus produce various pharmacologically relevant chemicals as secondary metabolites, including eudesmanes, flavonoids, guanidine alkaloids, acetylenic compounds, and germacrenes, the active compounds required for these benefits remain unknown. To investigate potential antimicrobial activities of Verbesina negrensis, crude extracts from plant aerial structures were evaluated. Following chemical fractionation, the chloroformic extract from Verbesina negrensis was subjected to bioassay-guided isolation using disk diffusion assays to determine antimicrobial activity. The active compound was characterized as 6β-cinnamoyloxy-1β-hydroxy-10α-metoxy-3-oxo-germacra-4,5Z-ene (1). Fractions containing 1 inhibited both Enterococcus faecalis (ATCC 29 212) and Staphylococcus aureus (ATCC 29213). The MIC for 1 was determined by microbroth dilution assay to be 64 µg/mL for both E. faecalis and S. aureus. Georg Thieme Verlag KG Stuttgart · New York.

Antimicrobial activity of extracts from Tamarindus indica L. leaves

PubMed Central

Escalona-Arranz, Julio César; Péres-Roses, Renato; Urdaneta-Laffita, Imilci; Camacho-Pozo, Miladis Isabel; Rodríguez-Amado, Jesús; Licea-Jiménez, Irina

2010-01-01

Tamarindus indica L. leaves are reported worldwide as antibacterial and antifungal agents; however, this observation is not completely accurate in the case of Cuba. In this article, decoctions from fresh and sun dried leaves, as well as fluid extracts prepared with 30 and 70% ethanol-water and the pure essential oil from tamarind leaves were microbiologically tested against Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Pseudomona aeruginosa and Candida albicans. Aqueous and fluid extracts were previously characterized by spectrophotometric determination of their total phenols and flavonoids, while the essential oil was chemically evaluated by gas chromatography/mass spectroscopy (GC/MS). Experimental data suggest phenols as active compounds against B. subtilis cultures, but not against other microorganisms. On the other hand, the essential oil exhibited a good antimicrobial spectrum when pure, but its relative low concentrations in common folk preparations do not allow for any good activity in these extracts. PMID:20931087

GC-MS characterization of n-hexane soluble fraction from dandelion (Taraxacum officinale Weber ex F.H. Wigg.) aerial parts and its antioxidant and antimicrobial properties.

PubMed

Ivanov, Ivan; Petkova, Nadezhda; Tumbarski, Julian; Dincheva, Ivayla; Badjakov, Ilian; Denev, Panteley; Pavlov, Atanas

2018-01-26

A comparative investigation of n-hexane soluble compounds from aerial parts of dandelion (Taraxacum officinale Weber ex F.H. Wigg.) collected during different vegetative stages was carried out. The GC-MS analysis of the n-hexane (unpolar) fraction showed the presence of 30 biologically active compounds. Phytol [14.7% of total ion current (TIC)], lupeol (14.5% of TIC), taraxasteryl acetate (11.4% of TIC), β-sitosterol (10.3% of TIC), α-amyrin (9.0% of TIC), β-amyrin (8.3% of TIC), and cycloartenol acetate (5.8% of TIC) were identified as the major components in n-hexane fraction. The unpolar fraction exhibited promising antioxidant activity - 46.7 mmol Trolox equivalents/g extract (determined by 1,1-diphenyl-2-picrylhydrazyl method). This fraction demonstrated insignificant antimicrobial activity and can be used in cosmetic and pharmaceutical industries.

Antimicrobial and physical-mechanical properties of agar-based films incorporated with grapefruit seed extract.

PubMed

Kanmani, Paulraj; Rhim, Jong-Whan

2014-02-15

The use of synthetic petroleum based packaging films caused serious environmental problems due to their difficulty in recycling and poor biodegradability. Therefore, present study was aimed to develop natural biopolymer-based antimicrobial packaging films as an alternative for the synthetic packaging films. As a natural antimicrobial agent, grapefruit seed extract (GSE) has been incorporated into agar to prepare antimicrobial packaging film. The films with different concentrations of GSE were prepared by a solvent casting method and the resulting composite films were examined physically and mechanically. In addition, the films were characterized by FE-SEM, XRD, FT-IR and TGA. The incorporation of GSE caused increase in color, UV barrier, moisture content, water solubility and water vapor permeability, while decrease in surface hydrophobicity, tensile strength and elastic modulus of the films. As the concentration of GSE increased from 0.6 to 13.3 μg/mL, the physical and mechanical properties of the films were affected significantly. The addition of GSE changed film microstructure of the film, but did not influence the crystallinity of agar and thermal stability of the agar-based films. The agar/GSE films exhibited distinctive antimicrobial activity against three test food pathogens, such as Listeria monocytogenes, Bacillus cereus and Escherichia coli. These results suggest that agar/GSE films have potential to be used in an active food packaging systems for maintaining food safety and extending the shelf-life of the packaged food. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

PubMed

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

2016-11-01

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

Characterizing the structure-function relationship reveals the mode of action of a novel antimicrobial peptide, P1, from jumper ant Myrmecia pilosula.

PubMed

Tseng, Tien-Sheng; Tsai, Keng-Chang; Chen, Chinpan

2017-06-01

Microbial infections of antibiotic-resistant strains cause serious diseases and have a significant impact on public health worldwide, so novel antimicrobial drugs are urgently needed. Insect venoms, a rich source of bioactive components containing antimicrobial peptides (AMPs), are attractive candidates for new therapeutic agents against microbes. Recently, a novel peptide, P1, identified from the venom of the Australian jumper ant Myrmecia pilosula, showed potent antimicrobial activities against both Gram-negative and Gram-positive bacteria, but its structure-function relationship is unknown. Here, we used biochemical and biophysical techniques coupled with computational simulations to explore the mode of action of P1 interaction with dodecylphosphocholine (DPC) micelles as a model membrane system. Our circular dichroism (CD) and NMR studies revealed an amphipathic α-helical structure for P1 upon interaction with DPC micelles. A paramagnetic relaxation enhancement approach revealed that P1 orients its α-helix segment (F6-G14) into DPC micelles. In addition, the α-helix segment could be essential for membrane permeabilization and antimicrobial activity. Moreover, the arginine residues R8, R11, and R15 significantly contribute to helix formation and membrane-binding affinity. The lysine residue K19 of the C-terminus functionally guides P1 to interact with DPC micelles in the early interaction stage. Our study provides insights into the mode of action of P1, which is valuable in modifying and developing potent AMPs as antibiotic drugs.

Antioxidant and antimicrobial properties of polyphenolic fractions from selected Moroccan red wines.

PubMed

Tenore, Gian Carlo; Basile, Adriana; Novellino, Ettore

2011-01-01

The present study is the first effort to a comprehensive evaluation of the antioxidant and antimicrobial activities of fractionated red wines from Morocco. The results obtained revealed that the wine samples were characterized by a higher phytochemical concentration than the same variety of wines with a different geographical origin and other more consumed red wines, confirming what was reported in a previous authors' work. The most phenolic-rich fractions were the ones containing phenolic acids and quercetin glucoronides from Syrah and Merlot wine samples while Cabernet Sauvignon exhibited the highest monomeric anthocyanin content. The antioxidant activity of wine extracts was tested by ferric reducing antioxidant power and 1,1-diphenyl-2-picrilhydrazyl assays. Samples revealed a higher reducing capacity than radical scavenging property and a good correlation between antioxidant activity and polyphenolic content values. As regards the antimicrobial properties, each fraction exhibited activity against a broad spectrum of food-borne microorganisms, revealing not only a moderate to high natural preserving capacity, but also potentially beneficial influence on human health. In consideration of the scarcity of data regarding composition and biological properties of Moroccan red wines, the present study may represent a valuable reference for wine consumers and producers. © 2011 Institute of Food Technologists®

Biosynthesis of silver nanoparticles using Alternanthera sessilis (Linn.) extract and their antimicrobial, antioxidant activities.

PubMed

Niraimathi, K L; Sudha, V; Lavanya, R; Brindha, P

2013-02-01

The present work focuses the use of the aqueous extract of Alternanthera sessilis Linn. (Amaranthaceae) in producing silver nanoparticles (AgNPs) from silver nitrate aqueous. Phytochemical analysis of the extract revealed the presence of alkaloid, tannins, ascorbic acid, carbohydrates and proteins and they serve as effective reducing and capping agents for converting silver nitrate into nanoparticles. The synthesized silver nanoparticles (AgNPs) were also tested for proteins and ascorbic acid. Its pH was also determined (5.63). The AgNPs obtained was characterized by UV-vis spectroscopy, FT-IR spectroscopy, SEM, Zeta sizer and TG-DSC. SEM images which revealed the presence of various shapes and sizes. FT-IR spectrum showed the AgNPs having a coating of proteins indicating a dual role of bio-molecules responsible for capping and efficient stabilization of the silver nanoparticles. Presence of impurities and melting point profile were screened by TG-DSC analyzer. AgNPs were synthesized from the silver nitrate through the reducing power of ascorbic acid present in A. sessilis leaves. In this study, we also investigated antimicrobial and antioxidant activity of green synthesized AgNPs. The antimicrobial activity is investigated by Bauer et al.'s method. Antioxidant activity was done by DPPH method. Copyright © 2012 Elsevier B.V. All rights reserved.

Synthesis, spectroscopic studies and electrochemistry of palladium (II) macrocyclic complexes derived from a new tetraazahalogen substituted ligands by template method and their antimicrobial and pesticidal activities

NASA Astrophysics Data System (ADS)

Masih, Iffat; Fahmi, Nighat

2011-09-01

A new series of Pd(II) macrocyclic complexes have been synthesized by template condensation of bis(benzil)4-chloro 1,2-phenylenediamine (ML 1) and bis(benzil)4-fluro 1,2-phenylenediamine (ML 2) respectively, with appropriate diamine i.e. 1,2-phenylenediamine, 4-chloro 1,2-phenylenediamine and 4-fluro 1,2-phenylenediamine in the presence of PdCl 2 to form complexes of the type [Pd(C 40H 26N 4ClF)]Cl 2, [Pd(C 40H 27N 4X)]Cl 2 and [Pd(C 40H 26N 4X 2)]Cl 2, where X = Cl, F. The complexes have been characterized with the help of elemental analysis, IR, 1H NMR, electronic spectra, conductance measurement, magnetic susceptibility, cyclic voltammetry and X-ray powder diffraction studies. On the basis of these studies a square planar geometry has been proposed around the metal ion. The newly synthesized ligands and their complexes have been screened for antimicrobial and pesticidal activities. The results obtained from bioassays indicate that this class of compounds can be utilized for the design of new substance with pesticidal activity and promising antimicrobial activity.

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

PubMed

Al-Bakri, Amal G; Afifi, Fatma U

2007-01-01

The aim of this study was to screen and evaluate the antimicrobial activity of indigenous Jordanian plant extracts, dissolved in dimethylsulfoxide, using the rapid XTT assay and viable count methods. XTT rapid assay was used for the initial screening of antimicrobial activity for the plant extracts. Antimicrobial activity of potentially active plant extracts was further assessed using the "viable plate count" method. Four degrees of antimicrobial activity (high, moderate, weak and inactive) against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, respectively, were recorded. The plant extracts of Hypericum triquetrifolium, Ballota undulata, Ruta chalepensis, Ononis natrix, Paronychia argentea and Marrubium vulgare had shown promising antimicrobial activity. This study showed that while both XTT and viable count methods are comparable when estimating the overall antimicrobial activity of experimental substances, there is no strong linear correlation between the two methods.

Physicochemical, antioxidant, DNA cleaving properties and antimicrobial activity of fisetin-copper chelates.

PubMed

Łodyga-Chruscińska, Elżbieta; Pilo, Maria; Zucca, Antonio; Garribba, Eugenio; Klewicka, Elżbieta; Rowińska-Żyrek, Magdalena; Symonowicz, Marzena; Chrusciński, Longin; Cheshchevik, Vitalij T

2018-03-01

Fisetin (3,3',4',7-tetrahydroxyflavone) metal chelates are of interest as this plant polyphenol has revealed broad prospects for its use as natural medicine in the treatment of various diseases. Metal interactions may change or enhance fisetin biological properties so understanding fisetin metal chelation is important for its application not only in medicine but also as a food additive in nutritional supplements. This work was aimed to determine and characterize copper complexes formed in different pH range at applying various metal/ligand ratios. Fisetin and Cu(II)-fisetin complexes were characterized by potentiometric titrations, UV-Vis (Ultraviolet-visible spectroscopy), EPR, ESI-MS, FTIR and cyclic voltammetry. Their effects on DNA were investigated by using circular dichroism, spectrofluorimetry and gel electrophoresis methods. The copper complex with the ratio of Cu(II)/fisetin 1/2 exhibited significant DNA cleavage activity, followed by complete degradation of DNA. The influence of copper(II) ions on antioxidant activity of fisetin in vitro has been studied using DPPH, ABTS and mitochondrial assays. The results have pointed out that fisetin or copper complexes can behave both as antioxidants or pro-oxidants. Antimicrobial activity of the compounds has been investigated towards several bacteria and fungi. The copper complex of Cu(II)/fisetin 1/2 ratio showed higher antagonistic activity against bacteria comparing to the ligand and it revealed a promising antifungal activity. Copyright © 2017 Elsevier Inc. All rights reserved.

Isolation and characterization of an endophytic fungal strain with potent antimicrobial and termiticidal activities from Port-Orford-Cedar

Treesearch

L. Sun; C.-Y. Hse; T. Shupe; M. Sun; X. Wang; K. Zhao

2015-01-01

Termites are responsible for an estimated US$1 billion annually in property damage, repairs, pest control, and prevention. There is an urgent need of finding a better alternative way to control and prevent termites. Port-Orford-Cedar (POC) has been known to have significant levels of natural durability and termiticidal activities due to its extractive contents. In this...

Synthesis, characterization and in silico designing of diethyl-3-methyl-5-(6-methyl-2-thioxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxamido) thiophene-2,4-dicarboxylate derivative as anti-proliferative and anti-microbial agents.

PubMed

Malani, Kalpesh; Thakkar, Sampark S; Thakur, Mukund Chandra; Ray, Arabinda; Doshi, Hiren

2016-10-01

A series of eight compounds diethyl-3-methyl-5-(6-methyl-2-thioxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxamido) thiophene-2,4-dicarboxilate (KM10-17) analogues have been prepared by conventional methods and characterized by IR, Mass, NMR and elemental analysis. In silico docking studies on Human topoisomerase IIbeta (PDB Id: 3QX3) have been performed for all molecules (KM10-17) synthesized. The compounds were tested for in vitro anti-proliferative activity on VERO and 786-O cell lines. Out of all the synthesized compounds, KM11 &KM16 showed moderate activity on both cell lines. In vitro anti-microbial activity was also checked against Bacillus subtilis (BS), Staphylococcus aurous (SA), Pseudomonas aeruginosa (PA), Escherichia coli (EC) and Candida albicans (CA) by well diffusion method. The compound KM11 was found to have highest zone of inhibition against BS, SA, PA and EC. The molecules KM13 and KM16 exhibited good activity against CA. The compounds KM14 and KM16 indicated good zone of inhibition against BS. Copyright © 2016 Elsevier Inc. All rights reserved.

Study of a series of cobalt(II) sulfonamide complexes: Synthesis, spectroscopic characterization, and microbiological evaluation against M. tuberculosis. Crystal structure of [Co(sulfamethoxazole)2(H2O)2]·H2O

NASA Astrophysics Data System (ADS)

Mondelli, Melina; Pavan, Fernando; de Souza, Paula C.; Leite, Clarice Q.; Ellena, Javier; Nascimento, Otaciro R.; Facchin, Gianella; Torre, María H.

2013-03-01

Nowadays, the research for new and better antimicrobial compounds is an important field due to the increase of immunocompromised patients, the use of invasive medical procedures and extensive surgeries, among others, that can affect the incidence of infections. Another big problem associated is the occurrence of drug-resistant microbial strains that impels a ceaseless search for new antimicrobial agents. In this context, a series of heterocyclic-sulfonamide complexes with Co(II) was synthesized and characterized with the aim of obtaining new antimicrobial compounds. The structural characterization was performed using different spectroscopic methods (UV-Vis, IR, and EPR). In spite of the fact that the general stoichiometry for all the complexes was Co(sulfonamide)2·nH2O, the coordination atoms were different depending on the coordinated sulfonamide. The crystal structure of [Co(sulfamethoxazole)2(H2O)2]·H2O was obtained by X-ray diffraction showing that Co(II) is in a slightly tetragonal distorted octahedron where sulfamethoxazole molecules act as a head-to-tail bridges between two cobalt atoms, forming polymeric chains. Besides, the activity against Mycobacterium tuberculosis, one of the responsible for tuberculosis, and the cytotoxicity on J774A.1 macrophage cells were evaluated.

Molecular characterization and immunological roles of avian IL-22 and its soluble receptor IL-22 binding protein

USDA-ARS?s Scientific Manuscript database

As a member of the interleukin (IL)-10 family, IL-22 is an important mediator in modulating tissue responses during inflammation. Through activation of STAT3-signaling cascades, IL-22 induces proliferative and anti-apoptotic pathways, as well as antimicrobial peptides (AMPs), that help prevent tissu...

Synthesis of a novel multi N-halamines siloxane precursor and its antimicrobial activity on cotton

NASA Astrophysics Data System (ADS)

Wu, Lin; Xu, Yan; Cai, Lu; Zang, Xiong; Li, Zhanxiong

2014-09-01

A novel N-halamine siloxane antibacterial precursor N-(3-triethoxysilylpropyl)-N‧- (N″‧-heptylcarbamido-N″-ethyl)-butanediamide (TSHCEB) was synthesized and characterized in this study. The compound was then tethered to the surface of cotton fabrics through covalent ether linkages, followed by exposure to dilute sodium hypochlorite solutions to confer the cotton fabrics antibacterial property. The chemical structure of the monomer was confirmed by FTIR, 1H NMR and MS, and the surface of the treated cotton fabrics was characterized by FTIR, TGA, SEM, and XPS analysis. The antimicrobial cotton materials were then challenged with Gram-negative Escherichia coli O157:H7 (ATCC 43895) and Gram-positive Staphylococcus aureus (ATCC 6538). Results showed that it provided excellent antimicrobial properties against E. coli O157:H7 and S. aureus via direct contacting for 2-15 min. The controlled release of diverse chlorines was proved by inhibition zone. The chlorine bonded to the coating was stable under standard washing test and routine storage, stability toward UVA irradiation was also investigated, and the lost chlorine could be regenerated by rechlorination. The new N-halamine antibacterial precursor can provide superior antibacterial property within a short contact time.

Multilayered co-electrospun scaffold containing silver sulfadiazine as a prophylactic against osteomyelitis: Characterization and biological in vitro evaluations

NASA Astrophysics Data System (ADS)

Heo, Min; Lee, Sang Jin; Heo, Dong Nyoung; Lee, Donghyun; Lim, Ho-Nam; Moon, Ji-Hoi; Kwon, Il Keun

2018-02-01

Bone related-bacterial diseases including wound infections and osteomyelitis (OM) still remain a serious problem. In this study, a hybrid co-electrospun membrane consisting of gelatin (GE) and Poly(D,L-lactide-co-glycolide) (PLGA) fibrous sheets containing different concentrations (0, 0.1, 0.5, and 1 wt%) of silver sulfadiazine (AgSD) was designed to provide for improved antimicrobial effect and biocompatibility. Well-defined products were characterized by physicochemical analyses. For biological in vitro assessments, mouse osteoblastic MC3T3-E1 cells were cultured on the scaffolds. This test was done in order to assay for cytotoxicity by measuring cell proliferation. Antibacterial activity against gram-negative Pseudomonas aeruginosa (P. aeruginosa), gram-positive Staphylococcus aureus (S. aureus), and Methicillin-resistant Staphylococcus aureus (MRSA) was also tested. These biological tests showed that GE/PLGA-AgSD scaffolds had good cell viability, as well as effective antimicrobial activity. These remarkable results suggest that GE/PLGA-AgSD scaffolds possess great potential for the treatment of OM and can find many uses in the field of bone tissue engineering.

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

PubMed

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

2010-11-01

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

Enhanced Cellular Internalization: A Bactericidal Mechanism More Relative to Biogenic Nanoparticles than Chemical Counterparts.

PubMed

Kumari, Madhuree; Shukla, Shatrunajay; Pandey, Shipra; Giri, Ved P; Bhatia, Anil; Tripathi, Tusha; Kakkar, Poonam; Nautiyal, Chandra S; Mishra, Aradhana

2017-02-08

Biogenic synthesis of silver nanoparticles for enhanced antimicrobial activity has gained a lot of momentum making it an urgent need to search for a suitable biocandidate which could be utilized for efficient capping and shaping of silver nanoparticles with enhanced bactericidal activity utilizing its secondary metabolites. Current work illustrates the enhancement of antimicrobial efficacy of silver nanoparticles by reducing and modifying their surface with antimicrobial metabolites of cell free filtrate of Trichoderma viride (MTCC 5661) in comparison to citrate stabilized silver nanoparticles. Nanoparticles were characterized by visual observations, UV-visible spectroscopy, zetasizer, and transmission electron microscopy (TEM). Synthesized particles were monodispersed, spherical in shape and 10-20 nm in size. Presence of metabolites on surface of biosynthesized silver nanoparticles was observed by gas chromatography-mass spectroscopy (GC-MS), energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The antimicrobial activity of both silver nanoparticles was tested against Shigella sonnei, Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive) by growth inhibition curve analysis and colony formation unit assay. Further, it was noted that internalization of biosynthesized nanoparticles inside the bacterial cell was much higher as compared to citrate stabilized particles which in turn lead to higher production of reactive oxygen species. Increase in oxidative stress caused severe damage to bacterial membrane enhancing further uptake of particles and revoking other pathways for bacterial disintegration resulting in complete and rapid death of pathogens as evidenced by fluorescein diacetate/propidium iodide dual staining and TEM. Thus, study reveals that biologically synthesized silver nanoarchitecture coated with antimicrobial metabolites of T. viride was more potent than their chemical counterpart in killing of pathogenic bacteria.

Lawsonia inermis-mediated synthesis of silver nanoparticles: activity against human pathogenic fungi and bacteria with special reference to formulation of an antimicrobial nanogel.

PubMed

Gupta, Arpita; Bonde, Shital R; Gaikwad, Swapnil; Ingle, Avinash; Gade, Aniket K; Rai, Mahendra

2014-09-01

Lawsonia inermis mediated synthesis of silver nanoparticles (Ag-NPs) and its efficacy against Candida albicans, Microsporum canis, Propioniabacterium acne and Trichophyton mentagrophytes is reported. A two-step mechanism has been proposed for bioreduction and formation of an intermediate complex leading to the synthesis of capped nanoparticles was developed. In addition, antimicrobial gel for M. canis and T. mentagrophytes was also formulated. Ag-NPs were synthesized by challenging the leaft extract of L. inermis with 1 mM AgNO₃. The Ag-NPs were characterized by Ultraviolet-Visible (UV-Vis) spectrophotometer and Fourier transform infrared spectroscopy (FTIR). Transmission electron microscopy (TEM), nanoparticle tracking and analysis sytem (NTA) and zeta potential was measured to detect the size of Ag-NPs. The antimicrobial activity of Ag-NPs was evaluated by disc diffusion method against the test organisms. Thus these Ag-NPs may prove as a better candidate drug due to their biogenic nature. Moreover, Ag-NPs may be an answer to the drug-resistant microorganisms.

Characterization and Antilisterial Effect of Phosphatidylcholine Nanovesicles Containing the Antimicrobial Peptide Pediocin.

PubMed

de Mello, Michele Brauner; da Silva Malheiros, Patrícia; Brandelli, Adriano; Pesce da Silveira, Nádya; Jantzen, Márcia Monks; de Souza da Motta, Amanda

2013-03-01

Encapsulation may provide increased stability and antimicrobial efficiency to bacteriocins. In this work, the antilisterial peptide pediocin was encapsulated in nanovesicles prepared from partially purified soybean phosphatidylcholine. The maintenance of antimicrobial activity and properties of free and encapsulated pediocin was observed during 13 days at 4 °C, and after this period, the encapsulated pediocin retained 50 % its initial activity. The maintenance of the bioactive properties of free and encapsulated pediocin was observed against different species of Listeria, inhibiting Listeria monocytogenes, Listeria innocua and Listeria ivanovii. The size of vesicles containing pediocin was determined by dynamic light scattering as an average of 190 nm, with little change throughout the observation period. Polydispersity index values were around 0.201 and are considered satisfactory, indicating an adequate size distribution of liposomes. The efficiency of encapsulation was 80 %. Considering these results, the protocol used was appropriate for the encapsulation of this bacteriocin. Results demonstrate the production of stable nanoparticulate material. The maintenance of the properties of pediocin encapsulated in liposomes is fundamental to prospect the stability in different conditions of the food matrix.

Hydrothermal synthesis of bacterial cellulose-copper oxide nanocomposites and evaluation of their antimicrobial activity.

PubMed

Araújo, Inês M S; Silva, Robson R; Pacheco, Guilherme; Lustri, Wilton R; Tercjak, Agnieszka; Gutierrez, Junkal; Júnior, José R S; Azevedo, Francisco H C; Figuêredo, Girlene S; Vega, Maria L; Ribeiro, Sidney J L; Barud, Hernane S

2018-01-01

In this work, for the first time bacterial cellulose (BC) hydrogel membranes were used for the fabrication of antimicrobial cellulosic nanocomposites by hydrothermal deposition of Cu derivative nanoparticles (i.e.Cu(0) and CuxOy species). BC-Cu nanocomposites were characterized by FTIR, SEM, AFM, XRD and TGA, to study the effect of hydrothermal processing time on the final physicochemical properties of final products. XRD result show that depending on heating time (3-48h), different CuxOy phases were achieved. SEM and AFM analyses unveil the presence of the Cu(0) and copper CuxOy nanoparticles over BC fibrils while the surface of 3D network became more compact and smother for longer heating times. Furthermore, the increase of heating time placed deleterious effect on the structure of BC network leading to decrease of BC crystallinity as well as of the on-set degradation temperature. Notwithstanding, BC-Cu nanocomposites showed excellent antimicrobial activity against E. coli, S. aureus and Salmonella bacteria suggesting potential applications as bactericidal films. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mechanistic antimicrobial approach of extracellularly synthesized silver nanoparticles against gram positive and gram negative bacteria.

PubMed

Tamboli, Dhawal P; Lee, Dae Sung

2013-09-15

The development of eco-friendly and reliable processes for the synthesis of nanoparticles has attracted considerable interest in nanotechnology. In this study, an extracellular enzyme system of a newly isolated microorganism, Exiguobacterium sp. KNU1, was used for the reduction of AgNO₃ solutions to silver nanoparticles (AgNPs). The extracellularly biosynthesized AgNPs were characterized by UV-vis spectroscopy, Fourier transform infra-red spectroscopy and transmission electron microscopy. The AgNPs were approximately 30 nm (range 5-50 nm) in size, well-dispersed and spherical. The AgNPs were evaluated for their antimicrobial effects on different gram negative and gram positive bacteria using the minimum inhibitory concentration method. Reasonable antimicrobial activity against Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus was observed. The morphological changes occurred in all the microorganisms tested. In particular, E. coli exhibited DNA fragmentation after being treated with the AgNPs. Finally, the mechanism for their bactericidal activity was proposed according to the results of scanning electron microscopy and single cell gel electrophoresis. Copyright © 2013 Elsevier B.V. All rights reserved.

Characterization of Active Packaging Films Made from Poly(Lactic Acid)/Poly(Trimethylene Carbonate) Incorporated with Oregano Essential Oil.

PubMed

Liu, Dong; Li, Hongli; Jiang, Lin; Chuan, Yongming; Yuan, Minglong; Chen, Haiyun

2016-05-27

Antimicromial and antioxidant bioactive films based on poly(lactic acid)/poly(trimenthylene carbonate) films incorporated with different concentrations of oregano essential oil (OEO) were prepared by solvent casting. The antimicrobial, antioxidant, physical, thermal, microstructural, and mechanical properties of the resulting films were examined. Scanning electron microscopy analysis revealed that the cross-section of films became rougher when OEO was incorporated into PLA/PTMC blends. Differential scanning calorimetry analysis indicated that crystallinity of PLA phase decreased by the addition of OEO, but this did not affect the thermal stability of the films. Water vapor permeability of films slightly increased with increasing concentration of OEO. However, active PLA/PTMC/OEO composite films showed adequate barrier properties for food packaging application. The antimicrobial and antioxidant capacities were significantly improved with the incorporation of OEO (p < 0.05). The results demonstrated that an optimal balance between the mechanical, barrier, thermal, antioxidant, and antimicrobial properties of the films was achieved by the incorporation of 9 wt % OEO into PLA/PTMC blends.

Nanosized Drug Delivery Systems in Gastrointestinal Targeting: Interactions with Microbiota

PubMed Central

Karavolos, Michail; Holban, Alina

2016-01-01

The new age of nanotechnology has signaled a stream of entrepreneurial possibilities in various areas, form industry to medicine. Drug delivery has benefited the most by introducing nanostructured systems in the transport and controlled release of therapeutic molecules at targeted sites associated with a particular disease. As many nanosized particles reach the gastrointestinal tract by various means, their interactions with the molecular components of this highly active niche are intensively investigated. The well-characterized antimicrobial activities of numerous nanoparticles are currently being considered as a reliable and efficient alternative to the eminent world crisis in antimicrobial drug discovery. The interactions of nanosystems present in the gastrointestinal route with host microbiota is unavoidable; hence, a major research initiative is needed to explore the mechanisms and effects of these nanomaterials on microbiota and the impact that microbiota may have in the outcome of therapies entailing drug delivery nanosystems through the gastrointestinal route. These coordinated studies will provide novel techniques to replace or act synergistically with current technologies and help develop new treatments for major diseases via the discovery of unique antimicrobial molecules. PMID:27690060

Characterization and bacterial anti-adherent effect on modified PMMA denture acrylic resin containing platinum nanoparticles

PubMed Central

2014-01-01

PURPOSE This study characterized the synthesis of a modified PMMA (Polymethyl methacrylate) denture acrylic loading platinum nanoparticles (PtN) and assessed its bacterial inhibitory efficacy to produce novel antimicrobial denture base material. MATERIALS AND METHODS Polymerized PMMA denture acrylic disc (20 mm × 2 mm) specimens containing 0 (control), 10, 50, 100 and 200 mg/L of PtN were fabricated respectively. The obtained platinum-PMMA nanocomposite (PtNC) was characterized by TEM (transmission electron microscopy), SEM/EDX (scanning electron microscope/energy dispersive X-ray spectroscopy), thermogravimetric and atomic absorption spectrophotometer analysis. In antimicrobial assay, specimens were placed on the cell culture plate, and 100 µL of microbial suspensions of S. mutans (Streptococcus mutans) and S. sobrinus (Streptococcus sobrinus) were inoculated then incubated at 37℃ for 24 hours. The bacterial attachment was tested by FACS (fluorescence-activated cell sorting) analysis after staining with fluorescent probe. RESULTS PtN were successfully loaded and uniformly immobilized into PMMA denture acrylic with a proper thermal stability and similar surface morphology as compared to control. PtNC expressed significant bacterial anti-adherent effect rather than bactericidal effect above 50 mg/L PtN loaded when compared to pristine PMMA (P=.01) with no or extremely small amounts of Pt ion eluted. CONCLUSION This is the first report on the synthesis and its antibacterial activity of Pt-PMMA nanocomposite. PMMA denture acrylic loading PtN could be a possible intrinsic antimicrobial denture material with proper mechanical characteristics, meeting those specified for denture bases. For clinical application, future studies including biocompatibility, color stability and warranting the long-term effect were still required. PMID:25006385

Covalent Dimer Species of β-Defensin Defr1 Display Potent Antimicrobial Activity against Multidrug-Resistant Bacterial Pathogens▿

PubMed Central

Taylor, Karen; McCullough, Bryan; Clarke, David J.; Langley, Ross J.; Pechenick, Tali; Hill, Adrian; Campopiano, Dominic J.; Barran, Perdita E.; Dorin, Julia R.; Govan, John R. W.

2007-01-01

Beta defensins comprise a family of cationic, cysteine-rich antimicrobial peptides, predominantly expressed at epithelial surfaces. Previously we identified a unique five-cysteine defensin-related peptide (Defr1) that, when synthesized, is a mixture of dimeric isoforms and exhibits potent antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa. Here we report that Defr1 displays antimicrobial activity against an extended panel of multidrug-resistant nosocomial pathogens for which antimicrobial treatment is limited or nonexistent. Defr1 fractions were collected by high-pressure liquid chromatography and analyzed by gel electrophoresis and mass spectrometry. Antimicrobial activity was initially investigated with the type strain Pseudomonas aeruginosa PAO1. All fractions tested displayed equivalent, potent antimicrobial activity levels comparable with that of the unfractionated Defr1. However, use of an oxidized, monomeric six-cysteine analogue (Defr1 Y5C), or of reduced Defr1, gave diminished antimicrobial activity. These results suggest that the covalent dimer structure of Defr1 is crucial to antimicrobial activity; this hypothesis was confirmed by investigation of a synthetic one-cysteine variant (Defr1-1cys). This gave an activity profile similar to that of synthetic Defr1 but only in an oxidized, dimeric form. Thus, we have shown that covalent, dimeric molecules based on the Defr1 β-defensin sequence demonstrate antimicrobial activity even in the absence of the canonical cysteine motif. PMID:17353239

Biosynthesis, characterization and antimicrobial action of silver nanoparticles from root bark extract of Berberislycium Royle.

PubMed

Mehmood, Ansar; Murtaza, Ghulam; Bhatti, Tariq Mahmood; Kausar, Rehana; Ahmed, Muhammad Jamil

2016-01-01

Various biological methods are being recognized for the fabrication of silver nanoparticles, which are used in several fields. The phytosynthesis of nanoparticles came out as a cost effective and enviro-friendly approach. When root bark extract of Berberis lycium was treated with silver ions, they reduced to silver nanoparticles, which were spherical, crystalline, size ranged from 10-100nm and capped by biomolecules. Synthesized silver nanoparticles were characterized by UV-visible spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD) and Fourier Transform Infra Red Spectroscopy (FTIR). The plant mediated synthesized silver nanoparticles showed pronounced antimicrobial activities against both Gram negative bacteria (Escherichia coli, Klebseilla pneumoniae, Pseudomonas aeruginosa) and Gram positive bacteria (Staphylococcus aureus and Bacillus subtilis). The plant mediated process proved to be non-toxic and low cost contender as reducing agent for synthesizing stable silver nanoparticles.

Synthesis, spectral, and anti-microbial studies of thioiminium iodides and amine hydrochlorides.

PubMed

Britto, Sebastian; Renaud, Philippe; Nallu, Maruthai

2014-01-01

To avoid the undesired deprotonation during the addition of organolithium and organomagnesium reagents to ketones, the thioiminium salts, easily prepared from lactams and amides are converted into 2,2-disubstituted and 2-monosubstituted amines by reaction with simple nucleophiles such as organocerium and organocopper reagents. The reaction of thioiminium iodides with organocerium reagents derived by transmetalation of corresponding lithium reagents with anhydrous cerium(III) chloride has been investigated. These thioiminium iodides act as good electrophiles and accept alkylceriums towards bisaddition. The newly synthesized amines have been characterized by 1H and 13C NMR, IR and mass spectra. The amines have been converted into their hydrochlorides and characterized by COSY. These hydrochlorides have been subjected to antimicrobial screening with clinically isolated microorganisms, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi and Candida albicans. The hydrochlorides show quite good activity against these bacteria and fungus. Copyright © 2013 Elsevier B.V. All rights reserved.

Anti-phytopathogen potential of endophytic actinobacteria isolated from tomato plants (Lycopersicon esculentum) in southern Brazil, and characterization of Streptomyces sp. R18(6), a potential biocontrol agent.

PubMed

de Oliveira, Margaroni Fialho; da Silva, Mariana Germano; Van Der Sand, Sueli T

2010-09-01

Tomato plants (Lycopersicon esculentum) are highly susceptible to phytopathogen attack. The resulting intensive application of pesticides on tomato crops can affect the environment and health of humans and animals. The objective of this study was to select potential biocontrol agents among actinobacteria from tomato plants, in a search for alternative phytopathogen control. We evaluated 70 endophytic actinobacteria isolated from tomato plants in southern Brazil, testing their antimicrobial activity, siderophore production, indoleacetic acid production, and phosphate solubility. The actinomycete isolate with the highest antimicrobial potential was selected using the agar-well diffusion method, in order to optimize conditions for the production of compounds with antimicrobial activity. For this study, six growth media (starch casein-SC, ISP2, Bennett's, Sahin, Czapek-Dox, and TSB), three temperatures (25 degrees C, 30 degrees C, and 35 degrees C) and different pH were tested. Of the actinobacteria tested, 88.6% showed antimicrobial activity against at least one phytopathogen, 72.1% showed a positive reaction for indoleacetic acid production, 86.8% produced siderophores and 16.2% showed a positive reaction for phosphate solubility. Isolate R18(6) was selected due to its antagonistic activity against all phytopathogenic microorganisms tested in this study. The best conditions for production were observed in the SC medium, at 30 degrees C and pH 7.0. The isolate R18(6) showed close biochemical and genetic similarity to Streptomyces pluricolorescens. Copyright 2010 Elsevier Masson SAS. All rights reserved.

Antimicrobial evaluation of novel poly-lactic acid based nanocomposites incorporated with bioactive compounds in-vitro and in refrigerated vacuum-packed cooked sausages.

PubMed

Rezaeigolestani, Mohammadreza; Misaghi, Ali; Khanjari, Ali; Basti, Afshin Akhondzadeh; Abdulkhani, Ali; Fayazfar, Samira

2017-11-02

Biodegradability and antimicrobial activity of food packaging materials are among the most attractive parameters in modern food industries. In order to develop biodegradable poly-lactic acid (PLA) film to antibacterial nanocomposites, different concentration of Zataria multiflora Bioss. essential oil (ZME), propolis ethanolic extract (PEE) and cellulose nanofiber (CNF) were incorporated to the polymer by solvent casting method. The resulting films were characterized by mechanical and physical tests and their antimicrobial application was evaluated in-vitro against four common foodborne pathogens and in vacuum-packed cooked sausages during refrigerated storage. Mechanical examination revealed that addition of ZME and PEE made films more flexible and incorporation of CNF improved almost all mechanical parameters tested. Moreover, according to physical analysis, incorporation of 0.5% v/v ZME to the composite primary solutions improved water vapor permeability of the resulting films. Almost all of the active films were effective against the tested bacteria except for PLA/PEE films, and maximum antibacterial effects recorded for the films containing both ZME and PEE. Based on the microbiological and sensory evaluation of the sausages, all of the PLA/1%ZME/PEE composites increased the shelf life to >40days. The results indicate that incorporation of natural antimicrobial substances such as ZME and PEE to packaging material could be an interesting approach in development of active packaging material without significant negative effect on polymer technical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Antimicrobial drugs encapsulated in fibrin nanoparticles for treating microbial infested wounds.

PubMed

Alphonsa, B Maria; Sudheesh Kumar, P T; Praveen, G; Biswas, Raja; Chennazhi, K P; Jayakumar, R

2014-05-01

In vitro evaluation of antibacterial and antifungal drugs encapsulated fibrin nanoparticles to prove their potential prospect of using these nanocomponent for effective treatment of microbial infested wounds. Surfactant-free oil-in-water emulsification-diffusion method was adopted to encapsulate 1 mg/ml each of antimicrobial drugs (Ciprofloxacin and Fluconazole) in 4 ml of aqueous fibrinogen suspension and subsequent thrombin mediated cross linking to synthesize drug loaded fibrin nanoparticles. Ciprofloxacin loaded fibrin nanoparticles (CFNPs) showed size range of 253 ± 6 nm whereas that of Fluconazole loaded fibrin nanoparticles (FFNPs) was 260 ± 10 nm. Physico chemical characterizations revealed the firm integration of antimicrobial drugs within fibrin nanoparticles. Drug release studies performed at physiological pH 7.4 showed a release of 16% ciprofloxacin and 8% of fluconazole while as the release of ciprofloxacin at alkaline pH 8.5, was 48% and that of fluconazole was 37%. The antimicrobial activity evaluations of both drug loaded systems independently showed good antibacterial activity against Escherichia coli (E.coli), Staphylococcus aureus (S. aureus) and antifungal activity against Candida albicans (C. albicans). The in vitro toxicity of the prepared drug loaded nanoparticles were further analyzed using Human dermal fibroblast cells (HDF) and showed adequate cell viability. The efficacies of both CFNPs and FFNPs for sustained delivery of encapsulated anti microbial drugs were evaluated in vitro suggesting its potential use for treating microbial infested wounds (diabetic foot ulcer).

Antimicrobial constituents of peel and seeds of camu-camu (Myrciaria dubia).

PubMed

Kaneshima, Tai; Myoda, Takao; Toeda, Kazuki; Fujimori, Takane; Nishizawa, Makoto

2017-08-01

Various antimicrobial constituents of camu-camu fruit were isolated. Acylphloroglucinol (compound 1) and rhodomyrtone (compound 2) were isolated from the peel of camu-camu (Myrciaria dubia) fruit, while two other acylphloroglucinols (compounds 3 and 4) were obtained from camu-camu seeds. The structures of the isolated compounds were characterized by spectrophotometric methods. Compounds 1 and 4 were confirmed to be new acylphloroglucinols with different substituents at the C7 or C9 position of 2, and were named myrciarone A and B, respectively. Compound 3 was determined to be isomyrtucommulone B. This is the first report of the isolation of 3 from a natural resource. The antimicrobial activities of compounds 1, 3, and 4 were similar to those of 2, and the minimum inhibitory concentrations were either similar to or lower than that of kanamycin. These results suggest that the peel and seeds of camu-camu fruit could be utilized for therapeutic applications.

Identification, Purification and Characterization of Laterosporulin, a Novel Bacteriocin Produced by Brevibacillus sp. Strain GI-9

PubMed Central

Singh, Pradip Kumar; Chittpurna; Ashish; Sharma, Vikas; Patil, Prabhu B.; Korpole, Suresh

2012-01-01

Background Bacteriocins are antimicrobial peptides that are produced by bacteria as a defense mechanism in complex environments. Identification and characterization of novel bacteriocins in novel strains of bacteria is one of the important fields in bacteriology. Methodology/Findings The strain GI-9 was identified as Brevibacillus sp. by 16 S rRNA gene sequence analysis. The bacteriocin produced by strain GI-9, namely, laterosporulin was purified from supernatant of the culture grown under optimal conditions using hydrophobic interaction chromatography and reverse-phase HPLC. The bacteriocin was active against a wide range of Gram-positive and Gram-negative bacteria. MALDI-TOF experiments determined the precise molecular mass of the peptide to be of 5.6 kDa and N-terminal sequencing of the thermo-stable peptide revealed low similarity with existing antimicrobial peptides. The putative open reading frame (ORF) encoding laterosporulin and its surrounding genomic region was fished out from the draft genome sequence of GI-9. Sequence analysis of the putative bacteriocin gene did not show significant similarity to any reported bacteriocin producing genes in database. Conclusions We have identified a bacteriocin producing strain GI-9, belonging to the genus Brevibacillus sp. Biochemical and genomic characterization of laterosporulin suggests it as a novel bacteriocin with broad spectrum antibacterial activity. PMID:22403615

Identification, purification and characterization of laterosporulin, a novel bacteriocin produced by Brevibacillus sp. strain GI-9.

PubMed

Singh, Pradip Kumar; Chittpurna; Ashish; Sharma, Vikas; Patil, Prabhu B; Korpole, Suresh

2012-01-01

Bacteriocins are antimicrobial peptides that are produced by bacteria as a defense mechanism in complex environments. Identification and characterization of novel bacteriocins in novel strains of bacteria is one of the important fields in bacteriology. The strain GI-9 was identified as Brevibacillus sp. by 16 S rRNA gene sequence analysis. The bacteriocin produced by strain GI-9, namely, laterosporulin was purified from supernatant of the culture grown under optimal conditions using hydrophobic interaction chromatography and reverse-phase HPLC. The bacteriocin was active against a wide range of Gram-positive and Gram-negative bacteria. MALDI-TOF experiments determined the precise molecular mass of the peptide to be of 5.6 kDa and N-terminal sequencing of the thermo-stable peptide revealed low similarity with existing antimicrobial peptides. The putative open reading frame (ORF) encoding laterosporulin and its surrounding genomic region was fished out from the draft genome sequence of GI-9. Sequence analysis of the putative bacteriocin gene did not show significant similarity to any reported bacteriocin producing genes in database. We have identified a bacteriocin producing strain GI-9, belonging to the genus Brevibacillus sp. Biochemical and genomic characterization of laterosporulin suggests it as a novel bacteriocin with broad spectrum antibacterial activity.

Characterization of Treponema spp. isolates from pigs with ear necrosis and shoulder ulcers.

PubMed

Svartström, Olov; Karlsson, Frida; Fellström, Claes; Pringle, Märit

2013-10-25

Ear necrosis and shoulder ulcers in pigs are animal welfare problems and ethical issues that can cause economic losses for producers. Spirochetes have been observed microscopically in scrapings from pig ulcers since the early 1900s, but have until recently not been cultured and therefore not characterized. In this study, 12 Treponema spp. isolates were acquired from porcine ear necrosis, shoulder ulcers and gingiva. DNA analysis of the 16S rRNA-tRNA(Ile) intergenic spacer region (ISR2) or the 16S rRNA gene revealed relatedness to oral treponemes found in dogs and humans. All isolates except one aligned into two clusters, Treponema pedis and Treponema sp. OMZ 840-like. The 16S rRNA gene of the remaining isolate shared 99% nucleotide identity with Treponema parvum. Genetic fingerprinting of the isolates was performed through random amplification of polymorphic DNA (RAPD). In addition, the isolates were characterized by biochemical tests, including api(®)ZYM, tryptophanase and hippuricase activity, and by testing the antimicrobial susceptibility to tiamulin, valnemulin, tylosin, tylvalosin, lincomycin and doxycycline using broth dilution. All isolates except two showed unique RAPD fingerprints, whereas metabolic activity tests could not differentiate between the isolates. The MICs of all antimicrobial agents tested were low. Copyright © 2013 Elsevier B.V. All rights reserved.

Photobactericidal porphyrin-cellulose nanocrystals: synthesis, characterization, and antimicrobial properties.

PubMed

Feese, Elke; Sadeghifar, Hasan; Gracz, Hanna S; Argyropoulos, Dimitris S; Ghiladi, Reza A

2011-10-10

Adherence and survival of pathogenic bacteria on surfaces leading to concomitant transmission to new hosts significantly contributes to the proliferation of pathogens, which in turn considerably increases the threat to human health, particularly by antibiotic-resistant bacteria. Consequently, more research into effective surface disinfection and alternative materials (fabrics, plastics, or coatings) with antimicrobial and other bioactive characteristics is desirable. This report describes the synthesis and characterization of cellulose nanocrystals that were surface-modified with a cationic porphyrin. The porphyrin was appended onto the cellulose surface via the Cu(I)-catalyzed Huisgen-Meldal-Sharpless 1,3-dipolar cycloaddition having occurred between azide groups on the cellulosic surface and porphyrinic alkynes. The resulting, generally insoluble, crystalline material, CNC-Por (5), was characterized by infrared and diffusion (1)H NMR spectroscopies, gel permeation chromatography, and thermogravimetric analysis. Although only suspended, and not dissolved, in an aqueous system, CNC-Por (5) showed excellent efficacy toward the photodynamic inactivation of Mycobacterium smegmatis and Staphylococcus aureus , albeit only slight activity against Escherichia coli . The synthesis, properties, and activity of CNC-Por (5) described herein serve as a benchmark toward our overall objectives of developing novel, potent, bioactive, photobactericidal materials that are effective against a range of bacteria, with potential utilization in the health care and food preparation industries.

LyeTxI-b, a Synthetic Peptide Derived From Lycosa erythrognatha Spider Venom, Shows Potent Antibiotic Activity in Vitro and in Vivo.

PubMed

Reis, Pablo V M; Boff, Daiane; Verly, Rodrigo M; Melo-Braga, Marcella N; Cortés, María E; Santos, Daniel M; Pimenta, Adriano M de C; Amaral, Flávio A; Resende, Jarbas M; de Lima, Maria E

2018-01-01

The antimicrobial peptide LyeTxI isolated from the venom of the spider Lycosa erythrognatha is a potential model to develop new antibiotics against bacteria and fungi. In this work, we studied a peptide derived from LyeTxI, named LyeTxI-b, and characterized its structural profile and its in vitro and in vivo antimicrobial activities. Compared to LyeTxI, LyeTxI-b has an acetylated N-terminal and a deletion of a His residue, as structural modifications. The secondary structure of LyeTxI-b is a well-defined helical segment, from the second amino acid to the amidated C-terminal, with no clear partition between hydrophobic and hydrophilic faces. Moreover, LyeTxI-b shows a potent antimicrobial activity against Gram-positive and Gram-negative planktonic bacteria, being 10-fold more active than the native peptide against Escherichia coli. LyeTxI-b was also active in an in vivo model of septic arthritis, reducing the number of bacteria load, the migration of immune cells, the level of IL-1β cytokine and CXCL1 chemokine, as well as preventing cartilage damage. Our results show that LyeTxI-b is a potential therapeutic model for the development of new antibiotics against Gram-positive and Gram-negative bacteria.

LyeTxI-b, a Synthetic Peptide Derived From Lycosa erythrognatha Spider Venom, Shows Potent Antibiotic Activity in Vitro and in Vivo

PubMed Central

Reis, Pablo V. M.; Boff, Daiane; Verly, Rodrigo M.; Melo-Braga, Marcella N.; Cortés, María E.; Santos, Daniel M.; Pimenta, Adriano M. de C.; Amaral, Flávio A.; Resende, Jarbas M.; de Lima, Maria E.

2018-01-01

The antimicrobial peptide LyeTxI isolated from the venom of the spider Lycosa erythrognatha is a potential model to develop new antibiotics against bacteria and fungi. In this work, we studied a peptide derived from LyeTxI, named LyeTxI-b, and characterized its structural profile and its in vitro and in vivo antimicrobial activities. Compared to LyeTxI, LyeTxI-b has an acetylated N-terminal and a deletion of a His residue, as structural modifications. The secondary structure of LyeTxI-b is a well-defined helical segment, from the second amino acid to the amidated C-terminal, with no clear partition between hydrophobic and hydrophilic faces. Moreover, LyeTxI-b shows a potent antimicrobial activity against Gram-positive and Gram-negative planktonic bacteria, being 10-fold more active than the native peptide against Escherichia coli. LyeTxI-b was also active in an in vivo model of septic arthritis, reducing the number of bacteria load, the migration of immune cells, the level of IL-1β cytokine and CXCL1 chemokine, as well as preventing cartilage damage. Our results show that LyeTxI-b is a potential therapeutic model for the development of new antibiotics against Gram-positive and Gram-negative bacteria. PMID:29681894

Antimicrobial Activity of Bacillus Persicus 24-DSM Isolated from Dead Sea Mud.

PubMed

Al-Karablieh, Nehaya

2017-01-01

Dead Sea is a hypersaline lake with 34% salinity, gains its name due to the absence of any living macroscopic creatures. Despite the extreme hypersaline environment, it is a unique ecosystem for various halophilic microorganisms adapted to this environment. Halophilic microorganisms are known for various potential biotechnological applications, the purpose of the current research is isolation and screening of halophilic bacteria from Dead Sea mud for potential antimicrobial applications. Screening for antagonistic bacteria was conducted by bacterial isolation from Dead Sea mud samples and agar plate antagonistic assay. The potential antagonistic isolates were subjected to biochemical characterization and identification by 16S-rRNA sequencing. Among the collected isolates, four isolates showed potential antagonistic activity against Bacillus subtilis 6633 and Escherichia coli 8739. The most active isolate (24-DSM) was subjected for antagonistic activity and minimal inhibitory concentration against different gram positive and negative bacterial strains after cultivation in different salt concentration media. Results: The results of 16S-rRNA analysis revealed that 24-DSM is very closely related to Bacillus persicus strain B48, which was isolated from hypersaline lake in Iran. Therefore, the isolate 24-DSM is assigned as a new strain of B. persicusi isolated from the Dead Sea mud. B. persicusi 24-DSM showed higher antimicrobial activity, when it was cultivated with saline medium, against all tested bacterial strains, where the most sensitive bacterial strain was Corynebacterium diphtheria 51696.

Chemical Composition, Antimicrobial Activity, and Mode of Action of Essential Oils against Paenibacillus larvae, Etiological Agent of American Foulbrood on Apis mellifera.

PubMed

Pellegrini, María C; Alonso-Salces, Rosa M; Umpierrez, María L; Rossini, Carmen; Fuselli, Sandra R

2017-04-01

This study aimed to characterize the chemical composition of Aloysia polystachia, Acantholippia seriphioides, Schinus molle, Solidago chilensis, Lippia turbinata, Minthostachys mollis, Buddleja globosa, and Baccharis latifolia essential oils (EOs), and to evaluate their antibacterial activities and their capacity to provoke membrane disruption in Paenibacillus larvae, the bacteria that causes the American Foulbrood (AFB) disease on honey bee larvae. The relationship between the composition of the EOs and these activities on P. larvae was also analyzed. Monoterpenes were the most abundant compounds in all EOs. All EOs showed antimicrobial activity against P. larvae and disrupted the cell wall and cytoplasmic membrane of P. larvae provoking the leakage of cytoplasmic constituents (with the exception of B. latifolia EO). While, the EOs' antimicrobial activity was correlated most strongly to the content of pulegone, carvone, (Z)-β-ocimene, δ-cadinene, camphene, terpinen-4-ol, elemol, β-pinene, β-elemene, γ-cadinene, α-terpineol, and bornyl acetate; the volatiles that better explained the membrane disruption were carvone, limonene, cis-carvone oxide, pentadecane, trans-carvyl acetate, trans-carvone oxide, trans-limonene oxide, artemisia ketone, trans-carveol, thymol, and γ-terpinene (positively correlated) and biciclogermacrene, δ-2-carene, verbenol, α-pinene, and α-thujene (negatively correlated). The studied EOs are proposed as natural alternative means of control for the AFB disease. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Inhibitory activity of honey against foodborne pathogens as influenced by the presence of hydrogen peroxide and level of antioxidant power.

PubMed

Taormina, P J; Niemira, B A; Beuchat, L R

2001-09-28

Antimicrobial activity of honey has been attributed to hydrogen peroxide, which is produced by naturally occurring glucose oxidase, and phenolic compounds, although lethality of and inhibition by these and other components against microorganisms vary greatly, depending on the floral source of nectar. This study was undertaken to compare honeys from six floral sources for their inhibitory activity against Escherichia coli O157:H7, Salmonella typhimurium, Shigella sonnei, Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus. A disc assay revealed that development of zones of inhibition of growth depends on the type and concentration of honey, as well as the test pathogen. Growth of B. cereus was least affected. The inhibition of growth of S. sonnei, L. monocytogenes, and S. aureus in 25% solutions of honeys was reduced by treating solutions with catalase, indicating that hydrogen peroxide contributes to antimicrobial activity. Darker colored honeys were generally more inhibitory than light colored honeys. Darker honeys also contained higher antioxidant power. Since antimicrobial activity of the darker colored test honeys was not eliminated by catalase treatment, non-peroxide components such as antioxidants may contribute to controlling the growth of some foodborne pathogens. The antibacterial properties of honeys containing hydrogen peroxide and characterized by a range of antioxidant power need to be validated using model food systems.

The in-vitro evaluation of antibacterial, antifungal and cytotoxic properties of Marrubium vulgare L. essential oil grown in Tunisia

PubMed Central

2011-01-01

Background In order to validate its antiseptic and anticancer properties with respect to traditional uses, we have screened for the first time the antimicrobial activity of aerial parts of M. vulgare L. essential oil against different pathogenic microorganisms and the cytotoxic activity against HeLa cell lines. Methods The agar disk diffusion method was used to study the antibacterial activity of M. vulgare essential oil against 12 bacterial and 4 fungi strains. The disc diameters of zone of inhibition (DD), the minimum inhibitory concentrations (MIC) and the concentration inhibiting 50% (IC50) were investigated to characterize the antimicrobial activities of this essential oil. The in vitro cytotoxicity of M. vulgare essential oil was examined using a modified MTT assay; the viability and the IC50 were used to evaluate this test. Results The antimicrobial activity of the essential oil was investigated in order to evaluate its efficacy against the different tested microorganisms. The present results results showed a significant activity against microorganisms especially Gram (+) bacteria with inhibition zones and minimal inhibitory concentration values in the range of 6.6-25.2 mm and 1120-2600 μg/ml, respectively, whereas Gram (-) bacteria exhibited a higher resistance. As far as the antifungal activity, among four strains tested, Botrytis cinerea exhibited the strongest activity with inhibition zones of 12.6 mm. However, Fusarium solani, Penicillium digitatum and Aspergillus niger were less sensitive to M. vulgare essential oil. About the citotoxicity assay, this finding indicate the capability of this essential oil to inhibited the proliferation of HeLa cell lines under some conditions with IC50 value of 0.258 μg/ml. Conclusion This investigation showed that the M. vulgare essential oil has a potent antimicrobial activity against some Gram (+) pathogenic bacteria and Botrytis cinerea fungi. The present studies confirm the use of this essential oil as anticancer agent. Further research is required to evaluate the practical values of therapeutic applications. PMID:21936887

The in-vitro evaluation of antibacterial, antifungal and cytotoxic properties of Marrubium vulgare L. essential oil grown in Tunisia.

PubMed

Zarai, Zied; Kadri, Adel; Ben Chobba, Ines; Ben Mansour, Riadh; Bekir, Ahmed; Mejdoub, Hafedh; Gharsallah, Néji

2011-09-21

In order to validate its antiseptic and anticancer properties with respect to traditional uses, we have screened for the first time the antimicrobial activity of aerial parts of M. vulgare L. essential oil against different pathogenic microorganisms and the cytotoxic activity against HeLa cell lines. The agar disk diffusion method was used to study the antibacterial activity of M. vulgare essential oil against 12 bacterial and 4 fungi strains. The disc diameters of zone of inhibition (DD), the minimum inhibitory concentrations (MIC) and the concentration inhibiting 50% (IC50) were investigated to characterize the antimicrobial activities of this essential oil. The in vitro cytotoxicity of M. vulgare essential oil was examined using a modified MTT assay; the viability and the IC50 were used to evaluate this test. The antimicrobial activity of the essential oil was investigated in order to evaluate its efficacy against the different tested microorganisms. The present results results showed a significant activity against microorganisms especially Gram (+) bacteria with inhibition zones and minimal inhibitory concentration values in the range of 6.6-25.2 mm and 1120-2600 μg/ml, respectively, whereas Gram (-) bacteria exhibited a higher resistance. As far as the antifungal activity, among four strains tested, Botrytis cinerea exhibited the strongest activity with inhibition zones of 12.6 mm. However, Fusarium solani, Penicillium digitatum and Aspergillus niger were less sensitive to M. vulgare essential oil. About the citotoxicity assay, this finding indicate the capability of this essential oil to inhibited the proliferation of HeLa cell lines under some conditions with IC50 value of 0.258 μg/ml. This investigation showed that the M. vulgare essential oil has a potent antimicrobial activity against some Gram (+) pathogenic bacteria and Botrytis cinerea fungi. The present studies confirm the use of this essential oil as anticancer agent. Further research is required to evaluate the practical values of therapeutic applications.

The secrets of Oriental panacea: Panax ginseng.

PubMed

Colzani, Mara; Altomare, Alessandra; Caliendo, Matteo; Aldini, Giancarlo; Righetti, Pier Giorgio; Fasoli, Elisa

2016-01-01

The Panax ginseng root proteome has been investigated via capture with combinatorial peptide ligand libraries (CPLL) at three different pH values. Proteomic characterization by SDS-PAGE and nLC–MS/MS analysis, via LTQ-Orbitrap XL, led to the identification of a total of 207 expressed proteins. This quite large number of identifications was achieved by consulting two different plant databases: P. ginseng and Arabidopsis thaliana. The major groups of identified proteins were associated to structural species (19.2%), oxidoreductase (19.5%), dehydrogenases (7.6%) and synthases (9.0%). For the first time, an exploration of protein–protein interactions was performed by merging all recognized proteins and building an interactomic map, characterized by 196 nodes and 1554 interactions. Finally a peptidomic analysis was developed combining different in-silico enzymatic digestions to simulate the human gastrointestinal process: from 661 generated peptides, 95 were identified as possible bioactives and in particular 6 of them were characterized by antimicrobial activity. The present report offers new insight for future investigations focused on elucidation of biological properties of P. ginseng proteome and peptidome. Ginseng is a traditional oriental herbal remedy whose use is very diffused in all the world for its numerous pharmacological effects. However, the exact mechanism of action of ginseng components, both ginsenosides and proteins, is still unidentified. So the common use of ginseng requires strict investigations to assess both its efficiency and its safety. Although many reports have been published regarding the pharmacological effects of ginseng, little is known about the biochemical pathways of root. Proteomics analysis could be useful to elucidate the physiological pathways. In this manuscript, an integrated approach to proteomics and peptidomics will usher in exploration of Panax ginseng proteins and proteolytic peptides, obtained by in-silico gastrointestinal digestion, characterized by antimicrobial action. The present research would pave the way for better knowledge of metabolic functions connected with ginseng proteome and provide with new information necessary to understand better antimicrobial activity of P. ginseng.

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

PubMed Central

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

2018-01-01

Abstract Background 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). Methods 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. Results 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. Conclusions The prompt and brief empiric use of defined categories of broad-spectrum antimicrobials could not be associated with additional patient harm. PMID:29479546

Synthesis, structural and biochemical activity studies of a new hexadentate Schiff base ligand and its Cu(II), Ni(II), and Co(II) complexes

NASA Astrophysics Data System (ADS)

Ekmekcioglu, Pinar; Karabocek, Nevin; Karabocek, Serdar; Emirik, Mustafa

2015-11-01

A new Schiff base ligand (H2L) and its metal complexes have been prepared and characterized by elemental analysis, magnetic moment and spectral studies. The comparative in-vitro antimicrobial activities against various pathogens with reference to known antibiotics activity under the standard control of different concentrations revealed that the metal complexes (6-8) showed enhanced antimicrobial activities in general as compared to free ligand. As an exception, the free ligand showed better activity against Trichoderma. The antifungal activity experiments were performed in triplicate. The order of biochemical activity for metal complexes were observed as in the following. CuL > CoL > NiL, which is exactly same as the order of stability constants of these complexes. Additionally, we performed DFT and TD-DFT calculation for free ligand and Cu(II) complex to support the experimental data. The geometries of the Cu(II) complex have been optimized using the B3LYP level of theory. The theoretical calculations confirm that the copper (II) center exhibits a distorted square pyramidal geometry which is favored by experimental results.

Antiproliferative and antimicrobial efficacy of the compounds isolated from the roots of Oenothera biennis L.

PubMed

Singh, Shilpi; Dubey, Vijaya; Singh, Dhananjay Kumar; Fatima, Kaneez; Ahmad, Ateeque; Luqman, Suaib

2017-09-01

Oenothera biennis L., commonly known as evening primrose, harbours the flavonoids, steroids, tannins, fatty acids and terpenoids responsible for a diverse range of biological activity, such as antitumour, anti-arthritic and anti-inflammatory effects. In addition to the previous reports from aerial parts of this plant, studies related to antiproliferative or antimicrobial activity from the roots are warranted. To investigate antiproliferative and antimicrobial activity of compounds/mixture (1-8) isolated and characterized from the roots of O. biennis L. A possible mechanism of antiproliferative activity was also studied by targeting ornithine decarboxylase (ODC) and cathepsin D (CATD). Antiproliferative efficacy of the compounds/mixture was examined in selected cancer cell lines along with their probable mechanism of action. The antimicrobial activity was also studied against selected microbes (bacteria and fungi). Antiproliferative potential was evaluated by MTT assay against selected cell lines. The mechanism of action was studied spectrophotometrically by targeting ODC and CATD using both an in-vitro and an in-silico approach. The antimicrobial efficiency was analysed using the disc diffusion and broth dilution methods. Oenotheralanosterol B (3) and the mixture of oenotheralanosterol A and oenotheralanosterol B (4) exhibited antiproliferative activity against breast, hepatic, prostate and leukaemia cancer cell lines as well as in mouse macrophages (IC 50 8.35-49.69 μg/ml). Oenotheralanosterol B (3) and the mixture of oenotheralanosterol A and oenotheralanosterol B (4) displayed a strong molecular interaction with succinate dehydrogenase (binding energy -6.23 and -6.84 kcal/mol and Ki 27.03 and 9.6 μm, respectively). Oenotheralanosterol A (1), oenotheralanosterol B (3) and mixture of oenotheralanosterol A and oenotheralanosterol B (4) potently inhibited the ODC activity with IC 50 ranging from 4.65 ± 0.35 to 19.06 ± 4.16 μg/ml and also showed a strong interaction with ODC (BE -4.17 to -4.46 kcal/mol). Oenotheralanosterol A (1), cetoleilyl diglucoside (2), oenotheralanosterol B (3), dihydroxyprenylxanthone acetylated (6) and dihydroxyprenylxanthone (7) inhibited CATD activity (IC 50 3.95 ± 0.49 to 24.35 ± 2.89 μg/ml). The in-silico molecular interaction analysis of compounds with CATD revealed the non-specific interaction. A moderate antimicrobial activity was observed against selected microbes with a growth inhibition ranging from 6 to 14 mm and minimum inhibitory concentration between 125 and 500 μg/ml. Oenotheralanosterol B (3) and dihydroxyprenylxanthone acetylated (6) exhibited better antimicrobial activity with an MIC range from 62.50 to 500 μg/ml. Oenotheralanosterol B (3) exhibited stronger antiproliferative and antimicrobial potential with respect to the other compounds tested, whereas oenotheralanosterol A (1) was a potent inhibitor of ODC and CATD. Hence, it is suggested that these in-vitro findings could be studied further in vivo for biological activity, safety evaluation and derivatization to enhance potency and efficacy. © 2017 Royal Pharmaceutical Society.

Lactoferrin-Immobilized Surfaces onto Functionalized PLA Assisted by the Gamma-Rays and Nitrogen Plasma to Create Materials with Multifunctional Properties.

PubMed

Stoleru, Elena; Zaharescu, Traian; Hitruc, Elena Gabriela; Vesel, Alenka; Ioanid, Emil G; Coroaba, Adina; Safrany, Agnes; Pricope, Gina; Lungu, Maria; Schick, Christoph; Vasile, Cornelia

2016-11-23

Both cold nitrogen radiofrequency plasma and gamma irradiation have been applied to activate and functionalize the polylactic acid (PLA) surface and the subsequent lactoferrin immobilization. Modified films were comparatively characterized with respect to the procedure of activation and also with unmodified sample by water contact angle measurements, mass loss, X-ray photoelectron spectroscopy (XPS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM), and chemiluminescence measurements. All modified samples exhibit enhanced surface properties mainly those concerning biocompatibility, antimicrobial, and antioxidant properties, and furthermore, they are biodegradable and environmentally friendly. Lactoferrin deposited layer by covalent coupling using carbodiimide chemistry showed a good stability. It was found that the lactoferrin-modified PLA materials present significantly increased oxidative stability. Gamma-irradiated samples and lactoferrin-functionalized samples show higher antioxidant, antimicrobial, and cell proliferation activity than plasma-activated and lactoferrin-functionalized ones. The multifunctional materials thus obtained could find application as biomaterials or as bioactive packaging films.

Effective Design of Multifunctional Peptides by Combining Compatible Functions

PubMed Central

Diener, Christian; Garza Ramos Martínez, Georgina; Moreno Blas, Daniel; Castillo González, David A.; Corzo, Gerardo; Castro-Obregon, Susana; Del Rio, Gabriel

2016-01-01

Multifunctionality is a common trait of many natural proteins and peptides, yet the rules to generate such multifunctionality remain unclear. We propose that the rules defining some protein/peptide functions are compatible. To explore this hypothesis, we trained a computational method to predict cell-penetrating peptides at the sequence level and learned that antimicrobial peptides and DNA-binding proteins are compatible with the rules of our predictor. Based on this finding, we expected that designing peptides for CPP activity may render AMP and DNA-binding activities. To test this prediction, we designed peptides that embedded two independent functional domains (nuclear localization and yeast pheromone activity), linked by optimizing their composition to fit the rules characterizing cell-penetrating peptides. These peptides presented effective cell penetration, DNA-binding, pheromone and antimicrobial activities, thus confirming the effectiveness of our computational approach to design multifunctional peptides with potential therapeutic uses. Our computational implementation is available at http://bis.ifc.unam.mx/en/software/dcf. PMID:27096600

Mechanical, structural and physical aspects of chitosan-based films as antimicrobial dressings.

PubMed

Escárcega-Galaz, Ana A; Sánchez-Machado, Dalia I; López-Cervantes, Jaime; Sanches-Silva, Ana; Madera-Santana, Tomás J; Paseiro-Losada, Perfecto

2018-05-01

Chitosan is a biodegradable, non-toxic, and antimicrobial polymer. Chitosan films can be used as a dressing because they promote the healing of cutaneous ulcers. In this study, the mechanical, physical, and microbiological properties films of pure chitosan and films formulated with a glycerol-honey mixture were characterized. The films were smooth, homogenous, transparent, and porous, with no fractures or cracks. Additionally, it was found that all were resistant to breaking, that the tearing force was directly related to the chitosan concentration, and that the addition of honey and glycerol improved the elongation percentage. When evaluating the antimicrobial activity of the films against Pseudomonas aeruginosa and Klebsiella pneumoniae, the films were found to have an effect only by direct contact. In the films formulated with honey, the area of contact increased to 44%. The excellent color, structural, antimicrobial, and surface morphological properties of the newly developed films make them a promising alternative for use as a dressing for the healing of skin ulcers. Copyright © 2018 Elsevier B.V. All rights reserved.