Antimicrobial polylysine decorated nano-structures prepared through polymerization induced self-assembly (PISA)

2019 ◽  
Vol 10 (3) ◽  
pp. 336-344 ◽  
Author(s):  
L. Luppi ◽  
T. Babut ◽  
E. Petit ◽  
M. Rolland ◽  
D. Quemener ◽  
...  
Keyword(s):  
Diblock Copolymer ◽  
Self Assembly ◽  
Dispersion Polymerization ◽  
Antimicrobial Properties ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Nano Structures ◽  
Hydroxypropyl Methacrylate

Polylysine decorated diblock copolymer nano-objects are prepared by polymerization-induced self-assemblyviaRAFT dispersion polymerization of 2-hydroxypropyl methacrylate. Antimicrobial properties of the resulting nano-objects evaluated using a gram positive bacteria.

scholarly journals Polysulfobetaine-based diblock copolymer nano-objects via polymerization-induced self-assembly

2015 ◽  
Vol 6 (41) ◽  
pp. 7264-7273 ◽  
Author(s):  
Kay E. B. Doncom ◽  
Nicholas J. Warren ◽  
Steven P. Armes
Keyword(s):  
Diblock Copolymer ◽  
Self Assembly ◽  
Dispersion Polymerization ◽  
High Tolerance ◽  
Hydroxypropyl Methacrylate ◽  
Added Salt

A zwitterionic polysulfobetaine-based macro-CTA is used for the synthesis of spheres, worms or vesiclesviaaqueous RAFT dispersion polymerization of 2-hydroxypropyl methacrylate (HPMA). These new diblock copolymer nano-objects exhibit high tolerance of added salt.

scholarly journals The Carpathian lingonberry, raspberry and blackberry fruit extracts feature variable antimicrobial efficiency

2019 ◽  
pp. 27-32
Author(s):  
Emőke Mihok ◽  
Éva György ◽  
Endre Máthé
Keyword(s):  
Antimicrobial Properties ◽  
Ethanolic Extract ◽  
Inhibitory Effect ◽  
Diffusion Method ◽  
Gram Positive ◽  
Gram Negative ◽  
Antimicrobial Effects ◽  
Fruit Extracts ◽  
Gram Positive Bacteria ◽  
Wild Berries

Wild berry is an excellent source of phytonutrients and/or bioactive compounds associated with significant therapeutic properties, so that they have been utilized in folk medicine and traditional nutrition throughout centuries. Multiple health-promoting effects, such as anti-inflammatory, anti-diabetic, anti-heart and coronary disease properties were attributed to such wild berries. It has also been proved that berries could feature antimicrobial effects that could be of a great importance for the prevention of food-feed poisoning and fighting back antibiotic resistance. In this study, we investigated the antimicrobial properties of lingonberry (Vaccinium vitis-idaea), raspberry (Rubus idaeus) and blackberry (Rubus fruticosus) crude and ethanolic extracts prepared from fruits obtained from the spontaneous flora of Eastern Carpathian Mountains situated in Transylvania. The antimicrobial effect of crude and alcoholic extracts were assessed on four Gram-negative, five Gram-positive bacteria and one yeast species using the agar diffusion method. The studied bacteria can cause food or feed spoilage and foodborne diseases. Our results indicate the significant inhibitory effect of lingonberry extracts in the case of Gram-negative bacteria like Proteus vulgaris and Salmonella Hartford, while among Gram-positive bacteria the strongest inhibitory effect was observed for Bacillus species like B. cereus, B. subtilis, B. mojavensis and Micrococcus luteus. The raspberry and blackberry extracts featured milder inhibitory effects in the case of the studied bacteria species. Furthermore, we have studied the crude or ethanolic extract combinations associated antimicrobial effects synergistic/additive or antagonistic properties. Interestingly, the triple and double ethanolic extract mixes had stronger antimicrobial properties, whereas the crude extract mixes showed relatively reduced effects, if any. Our results indicate that the antimicrobial activity of studied fruit extracts obtained from wild berries can vary upon the applied extraction method and their combination formulae, so that all these considerations must be taken into account when such fruit extracts are considered for foodstuff development.

scholarly journals Purification of Bioactive Peptide with Antimicrobial Properties Produced by Saccharomyces cerevisiae

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 324 ◽  
Author(s):  
Shayma Thyab Gddoa Al-sahlany ◽  
Ammar Altemimi ◽  
Alaa Al-Manhel ◽  
Alaa Niamah ◽  
Naoufal Lakhssassi ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Antimicrobial Properties ◽  
Antibacterial Peptide ◽  
Inhibition Activity ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Viable Cells ◽  
Ph Range

A variety of organisms produce bioactive peptides that express inhibition activity against other organisms. Saccharomyces cerevisiae is considered the best example of a unicellular organism that is useful for studying peptide production. In this study, an antibacterial peptide was produced and isolated from Saccharomyces cerevisiae (Baker’s yeast) by an ultrafiltration process (two membranes with cut-offs of 2 and 10 kDa) and purified using the ÄKTA Pure 25 system. Antibacterial peptide activity was characterized and examined against four bacterial strains including Gram-positive and Gram-negative bacteria. The optimum condition for yeast growth and antibacterial peptide production against both Escherichia. coli and Klebsiella aerogenes was 25–30 °C within a 48 h period. The isolated peptide had a molecular weight of 9770 Da, was thermostable at 50–90 °C for 30 min, and tolerated a pH range of 5–7 at 4 °C and 25 °C during the first 24 h, making this isolated antibacterial peptides suitable for use in sterilization and thermal processes, which are very important aspect in food production. The isolated antibacterial peptide caused a rapid and steady decline in the number of viable cells from 2 to 2.3 log units of gram-negative strains and from 1.5 to 1.8 log units of gram-positive strains during 24 h of incubation. The isolated antibacterial peptide from Saccharomyces cerevisiae may present a potential biopreservative compound in the food industry exhibiting inhibition activity against gram-negative and gram-positive bacteria.

scholarly journals Semi-crystalline diblock copolymer nano-objects prepared via RAFT alcoholic dispersion polymerization of stearyl methacrylate

2015 ◽  
Vol 6 (10) ◽  
pp. 1751-1757 ◽  
Author(s):  
Mona Semsarilar ◽  
Nicholas J. W. Penfold ◽  
Elizabeth R. Jones ◽  
Steven P. Armes
Keyword(s):  
Diblock Copolymer ◽  
Self Assembly ◽  
Dispersion Polymerization ◽  
Local Order ◽  
Dsc Studies ◽  
The Core ◽  
Stearyl Methacrylate

Semi-crystalline diblock copolymer spheres, worms or vesicles are prepared by polymerization-induced self-assembly via RAFT dispersion polymerization of stearyl methacrylate. DSC studies confirm local order for the core-forming poly(stearyl methacrylate) chains.

scholarly journals Synthesis, Antibacterial and Antifungal Properties of Cyclohexane Tosyloxyimine Derivative

2019 ◽  
Vol 4 (3) ◽  
pp. 1-4
Author(s):  
Shoaib M
Keyword(s):  
Antimicrobial Agents ◽  
Sulfonyl Chloride ◽  
Antimicrobial Properties ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Bacteria And Fungi ◽  
Agar Well Diffusion Assay ◽  
Antibacterial And Antifungal ◽  
Candida Pseudotropicalis

Due to increasing antimicrobial resistance, functionally substituted cyclohexane derivatives are being explored as potential antimicrobial agents. Reaction of diethyl 4 - hydroxy - 6 - (hyd - roxyimino) - 4 - methyl - 2 - phenylcyclohexane - 1,3 - dicarboxylate with 4 - toluene sulfonyl chloride in boiling acetone in the presence of equimolar triethylamine resulted in formation of diethyl - 4 - hydroxy - 4 - methyl - 2 - phenyl - 6 - ((tosyloxy)imino) cyclohexane - 1,3 - dicarboxylate. The structure of novel compound was characterized by 1 H and 13 C NMR spectra and elemental analysis was performed. Agar well diffusion assay was used to screen novel compound against Gram - positive bacteria, Gram - negative bacteria and fungi. Test compound showed better antimicrobial properties against Gram - negative bac teria as compared to Gram - positive bacteria and fungi. Acinetobacter baumannii BDU - 32 was found to be most sensitive bacteria while Candida pseudotropicalis BDU MA88 was found to be most sensitive yeast.

scholarly journals Industrially-relevant polymerization-induced self-assembly formulations in non-polar solvents: RAFT dispersion polymerization of benzyl methacrylate

2015 ◽  
Vol 6 (16) ◽  
pp. 3054-3062 ◽  
Author(s):  
Matthew J. Derry ◽  
Lee A. Fielding ◽  
Steven P. Armes
Keyword(s):  
Diblock Copolymer ◽  
Self Assembly ◽  
Dispersion Polymerization ◽  
Mineral Oil ◽  
Polar Solvents ◽  
One Pot

Diblock copolymer spheres, worms and vesicles are prepared via RAFT dispersion polymerization of benzyl methacrylate in either mineral oil or a poly(α-olefin) using polymerization-induced self-assembly; an efficient ‘one-pot’ protocol is reported for spheres at 30% solids in mineral oil.

scholarly journals Synthesis of poly(stearyl methacrylate)-poly(2-hydroxypropyl methacrylate) diblock copolymer nanoparticles via RAFT dispersion polymerization of 2-hydroxypropyl methacrylate in mineral oil

2020 ◽  
Vol 11 (28) ◽  
pp. 4579-4590 ◽  
Author(s):  
Csilla György ◽  
Saul J. Hunter ◽  
Chloé Girou ◽  
Matthew J. Derry ◽  
Steven P. Armes
Keyword(s):  
Diblock Copolymer ◽  
Dispersion Polymerization ◽  
Mineral Oil ◽  
Hydroxypropyl Methacrylate ◽  
Stearyl Methacrylate

RAFT dispersion polymerization of 2-hydroxypropyl methacrylate produces diblock copolymer spheres, worms or vesicles in mineral oil; the Pickering emulsifier performance of the spheres is examined.

The antimicrobial properties of new synthetic porphyrins

2003 ◽  
Vol 07 (11) ◽  
pp. 755-760 ◽  
Author(s):  
Tatyana O. Philippova ◽  
Boris N. Galkin ◽  
Oksana Yu. Zinchenko ◽  
Maria Yu. Rusakova ◽  
Vladimir A. Ivanitsa ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antimicrobial Properties ◽  
Middle Level ◽  
Membrane Receptors ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Free Base ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

The antimicrobial activity of new meso-tetrakis(N-methyl-6-quinolinyl)-substituted porphyrins and meso-tetrakis(N-methyl-6-quinolinyl)-substituted chlorins is described. The dark toxicity and photosensitising potentials of free-base (TQP and TQC) and its Sn(IV)-complexes [(TQP)Sn(IV) and (TQC)Sn(IV)] were tested on Gram-positive (Staphylococus aureus), Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and two species of yeasts (Candida albicans and Rhodotorula bogoriensis). The results described in this paper show that TQP and (TQP)Sn(IV) did not inhibit the growth of S. aureus in the dark, but efficiently photosensitize the inactivation of this Gram-positive bacteria. These porphyrins have no appreciable photosensitizing activity towards Gram-negative bacteria. However, (TQP)Sn(IV) shows high dark toxicity against E. coli and P. aeruginosa. The free-base derivatives demonstrated dark activity only in the case of P. aeruginosa. We suppose that these meso-tetrakis(N-methyl-6-quinolinyl)-substituted porphyrins can bind to the Gram-negative bacteria outer membrane receptors that transported vitamin B12. The meso-substituted chlorins TQC and (TQC)Sn(IV) have shown similar efficiency in the dark- and photoinactivation of S. aureus. They revealed a middle level of dark toxicity towards Gram-negative bacteria. The Sn(IV)-complex of chlorin in comparison with free base and metalloporphyrins are more effective in photoinactivation of Gram-negative bacteria. Yeasts, such as Candida albicans and Rhodotorula bogoriensis are more sensitive to photodynamic inactivation as bacterial cells. The effects of (TQP)Sn(IV) and (TQC)Sn(IV) are more expressed than effects of free bases.

scholarly journals Preparation of Polypropylene/Silver Nanoparticles Nanocomposite Film and Evaluation of its Mechanical and Antimicrobial Properties w.r.t it’s Use in Packaging Applications

2021 ◽  
Vol 9 (VII) ◽  
pp. 3830-3838
Author(s):  
Rajesh Kumar Sahoo
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Polymer Nanocomposites ◽  
Nanocomposite Film ◽  
Antimicrobial Properties ◽  
Nanocomposite Films ◽  
Polypropylene Film ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Melt Compounding

Polypropylene/silver nanoparticles nanocomposite films were prepared by melt compounding method by using polypropylene pallets and silver nanoparticles powder. The physical properties of the virgin polypropylene film and nanocomposite films were evaluated by mechanical testing. The effect of various silver nanoparticles content in the polymer nanocomposites with respect to its antimicrobial efficacy against the Gram positive bacteria Escherichia coli and Gram positive bacteria Staphylococcus aureus were studied. Nanocomposite film containing higher percentage of silver nanoparticles loading showed 99.9 % efficacy against the bacteria as compared to virgin polypropylene film.

scholarly journals Antimicrobial Properties of MX-2401, an Expanded-Spectrum Lipopeptide Active in the Presence of Lung Surfactant

2011 ◽  
Vol 55 (8) ◽  
pp. 3720-3728 ◽  
Author(s):  
Dominique Dugourd ◽  
Haiyan Yang ◽  
Melissa Elliott ◽  
Raymond Siu ◽  
Jacob J. Clement ◽  
...  
Keyword(s):  
Lung Surfactant ◽  
Antimicrobial Properties ◽  
Coagulase Negative Staphylococci ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Gram Positive Bacteria ◽  
Lipopeptide Antibiotic ◽  
Hospital Acquired

ABSTRACTMX-2401 is an expanded-spectrum lipopeptide antibiotic selective for Gram-positive bacteria that is a semisynthetic analog of the naturally occurring lipopeptide amphomycin. It was active againstEnterococcusspp., including vancomycin-sensitiveEnterococcus(VSE),vanA-,vanB-, andvanC-positive vancomycin-resistantEnterococcus(VRE), linezolid- and quinupristin-dalfopristin-resistant isolates (MIC90of 4 μg/ml), methicillin-resistantStaphylococcus aureus(MRSA) and methicillin-sensitiveS. aureus(MSSA) (MIC90of 2 μg/ml), coagulase-negative staphylococci, including methicillin-sensitiveStaphylococcus epidermidis(MSSE) and methicillin-resistantS. epidermidis(MRSE) (MIC90of 2 μg/ml), andStreptococcusspp. including viridans group streptococci, and penicillin-resistant, penicillin-sensitive, penicillin-intermediate and macrolide-resistant isolates ofStreptococcus pneumoniae(MIC90of 2 μg/ml). MX-2401 demonstrated a dose-dependent postantibiotic effect varying from 1.5 to 2.4 h. Furthermore, MX-2401 was rapidly bactericidal at 4 times the MIC againstS. aureusandEnterococcus faecalis, with more than 99.9% reduction in viable bacterial attained at 4 and 24 h, respectively. The MICs of MX-2401 against MRSA, MSSA, VSE, and VRE strains serially exposed for 15 passages to sub- to supra-MICs of MX-2401 remained within three dilutions of the original MIC. In contrast to that of the lipopeptide daptomycin, the antibacterial activity of MX-2401 was not affectedin vitroby the presence of lung surfactant, and MX-2401 was activein vivoin the bronchial-alveolar pneumonia mouse model, in which daptomycin failed to show any activity. Moreover, the activity of MX-2401 was not as strongly dependent on the Ca2+concentration as is the activity of daptomycin. In conclusion, MX-2401 is a promising new-generation lipopeptide for the treatment of serious infections with Gram-positive bacteria, including hospital-acquired pneumonia.

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