Influence of synthetic peptide inducers on antibacterial activity of enterococci

2011 ◽  
Vol 2 (1) ◽  
pp. 9-13 ◽  
Author(s):  
E. Yermolenko ◽  
A. Chernysh ◽  
A. Kolobov ◽  
A. Suvorov
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Synthetic Peptide ◽  
Cyclic Peptides ◽  
Regulatory System ◽  
Probiotic Strain ◽  
Antagonistic Activity ◽  
Molecular Structures ◽  
Enterococcal Strain ◽  
Genes Encoding

Antibacterial activity of probiotic enterococci is often related to the production of bacteriocins. There is a variety of Enterococcus faecium strains which synthesise one or several enterocins including A, B, P, 96, L50AB and others. In this work we have analysed the probiotic strain E. faecium L3 whose genome contained the genes encoding enterocins А, В and a three-component regulatory system. All these genes were found to be expressed in enterococcal strain L3. Antimicrobial activity of the strain tested on the strains of Listeria monocytogenes and Streptococcus agalactiae was pheromone dependent. Chemically synthesised cyclic peptides (analogues and shorter derivates of EntF) with different molecular structures were able to increase the antagonistic activity of the strain E. faecium L3 in contrast to the strain E. faecium SF68, which does nоt have genes encoding enterocins А and В.

scholarly journals Lactobacillus reuteri AN417 cell-free culture supernatant as a novel antibacterial agent targeting oral pathogenic bacteria

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kyung Mi Yang ◽  
Ji-Sun Kim ◽  
Hye-Sung Kim ◽  
Young-Youn Kim ◽  
Jeong-Kyu Oh ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Periodontal Disease ◽  
Pathogenic Bacteria ◽  
Culture Supernatant ◽  
Lactobacillus Reuteri ◽  
Fusobacterium Nucleatum ◽  
Probiotic Strain ◽  
Genes Encoding ◽  
Acid Metabolites ◽  
Oral Pathogens

AbstractLactobacillus reuteri AN417 is a newly characterized probiotic strain. The activity of AN417 against oral pathogenic bacteria is unknown. We investigated the antibacterial activity of cell-free L. reuteri AN417 culture supernatant (LRS) against three oral pathogens: Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus mutans. P. gingivalis and F. nucleatum have been implicated in periodontal disease, whereas S. mutans causes dental caries. Exposing these oral pathogenic bacteria to LRS significantly reduced their growth rates, intracellular ATP levels, cell viability, and time-to-kill. The minimal inhibitory volume of LRS was 10% (v/v) against P. gingivalis, 20% (v/v) for F. nucleatum, and 30% (v/v) for S. mutans. LRS significantly reduced the integrity of biofilms and significantly suppressed the expression of various genes involved in P. gingivalis biofilm formation. The L. reuteri AN417 genome lacked genes encoding reuterin, reuteran, and reutericyclin, which are major antibacterial compounds produced in L. reuteri strains. LRS treated with lipase and α-amylase displayed decreased antibacterial activity against oral pathogens. These data suggest that the antibacterial substances in LRS are carbohydrates and/or fatty acid metabolites. Our results demonstrate that LRS has antimicrobial activity against dental pathogenic bacteria, highlighting its potential utility for the prevention and treatment of P. gingivalis periodontal disease.

scholarly journals Comparison of Antibacterial Activity ofLactobacillus plantarumStrains Isolated from Two Different Kinds of Regional Cheeses from Poland: Oscypek and Korycinski Cheese

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Aleksandra Ołdak ◽  
Dorota Zielińska ◽  
Anna Rzepkowska ◽  
Danuta Kołożyn-Krajewska
Keyword(s):  
Hydrogen Peroxide ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Broad Spectrum ◽  
Antimicrobial Properties ◽  
Antagonistic Activity ◽  
Antimicrobial Compounds ◽  
E Coli ◽  
Unpasteurized Milk ◽  
Protective Cultures

Oscypek and korycinski are traditional Polish cheeses, exclusively produced in Tatra and in Podlasie region, respectively, produced from raw, unpasteurized milk. The 29Lactobacillus plantarumstrains were isolated on MRS agar from 12 cheese samples and used as a material for study. The main purpose of the work was to assess the antimicrobial properties and recognition of selected strains for the unique antagonistic activity and preservation role in food. It has been found that the highest antimicrobial activity was observed in the case ofL. monocytogenesstrains; however, the level of that activity was different depending on theLb. plantarumstrain. Strains from oscypek produced broad spectrum, and a few strains isolated from korycinski cheese produced a narrow spectrum of antimicrobial compounds, other than organic acids and hydrogen peroxide. Moreover, the antagonistic activity shown byLb. plantarumstrains is connected with the source from which a given strain was isolated. Strains isolated from oscypek cheese represented stronger activity againstL. monocytogenes, whereas strains isolated from korycinski cheese were more active againstE. coli. StrainsLb. plantarumOs13 and Kor14 could be considered as good candidates for protective cultures to extend durability of food products.

Complexes of Cu (II) with a-Ketoglutaric Acid and 1- (o-tolyl) Biguanide Synthesis, characterization and biological Activity

2019 ◽  
Vol 70 (10) ◽  
pp. 3603-3610
Author(s):  
Madalina Mihalache ◽  
Cornelia Guran ◽  
Aurelia Meghea ◽  
Vasile Bercu ◽  
Ludmila Motelica ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Biological Activity ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Copper Complexes ◽  
Substrate Adhesion ◽  
Inert Substrate

The three copper complexes having a-ketoglutaric acid (H2A) and 1- (o-tolyl) biguanide (TB) ligands have been synthesized and characterized. The proposed formulas for these complexes are: [Cu(TB)(HA)]Cl (C1), [Cu(TB)(HA)CH3COO]�H2O (C2) and [Cu(TB)(HA)](NO3) (C3) where HA represents deprotonated H2A. The complexes obtained were tested for antibacterial activity against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853, antifungal activity on Candida albicans ATCC 10231 and antitumor activity on HeLa tumor cells. Due to the antitumor, antifungal, antimicrobial activity and inhibition of inert substrate adhesion, complexes synthesized could be used for potential therapeutic applications.

Design, Synthesis and Docking Studies of Some Novel Fluoroquinolone Compounds with Antibacterial Activity

2018 ◽  
Vol 69 (4) ◽  
pp. 815-822 ◽  
Author(s):  
Lucia Pintilie ◽  
Amalia Stefaniu ◽  
Alina Ioana Nicu ◽  
Maria Maganu ◽  
Miron Teodor Caproiu
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Molecular Docking ◽  
Drug Discovery ◽  
Elemental Analysis ◽  
Docking Studies ◽  
Receptor Protein ◽  
Chemical Methods ◽  
Design Synthesis ◽  
Gram Negative

A new series of fluoroquinolone compounds have been obtained by Gould-Jacobs method. The compounds have been characterized by physic-chemical methods (elemental analysis, FTIR, NMR, UV-Vis) and by antimicrobial activity against Gram-positive and Gram-negative microorganisms. For the synthesized compounds have been performed calculations of characteristics and molecular properties, using Spartan�14 Software from Wavefunction, Inc. Irvine, CA. and molecular docking studies using CLC Drug Discovery Workbench 2.4 software, to identify and visualize the most likely interaction ligand (fluoroquinolone) with the receptor protein.

Novel Synthesis of 4-Benzylidene-2-((1-phenyl-3,4-dihydroisoquinoline-2(1H)-yl)methyl) oxazol-5(4H)-one Derivatives Using 1,2,3,Tetrahydroisoquinoline and their Antimicrobial Activity

2020 ◽  
Vol 17 (5) ◽  
pp. 396-403
Author(s):  
Nalla Krishna Rao ◽  
Tentu Nageswara Rao ◽  
Botsa Parvatamma ◽  
Y. Prashanthi ◽  
Ravi Kumar Cheedarala
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Acetic Acid ◽  
Sodium Acetate ◽  
Good Activity ◽  
Activity Profile ◽  
Aryl Aldehydes ◽  
Chemical Structures ◽  
Novel Synthesis ◽  
Target Molecules

Aims: A series of six 4-benzylidene-2-((1-phenyl-3,4-dihydro isoquinoline-2(1H)-yl)methyloxazol- 5(4H)-one derivatives were synthesized by condensation of substituted aryl aldehydes with 2-(2-(1-phenyl-3,4- dihydro isoquinoline-2(1H)-acetamido)acetic acid in the presence of sodium acetate, acetic anhydride and zinc oxide as catalysts. Background: Novel Synthesis of 4-Benzylidene-2-((1-phenyl-3,4-dihy droisoquinoline-2(1H)-yl)methyl)oxazol- 5(4H)-one derivatives using 1,2,3,Tetrahydroisoquinoline and their antimicrobial activity. Objective: The title compounds can be synthesized from 1,2,3,4-tetrahydroisoquinoline. Methods: The target molecules, i.e., 4-benzylidene-2-((1-phenyl-3, 4-dihydro isoquinoline-2(1H)-yl) methyl) oxazol-5(4H)-one derivatives (8a-8f) have been synthesized from 1,2,3,4-tetrahydroisoquinoline which was prepared from benzoic acid in few steps. Results: All the six compounds were evaluated based on advanced spectral data (1H NMR, 13C NMR & LCMS), and the chemical structures of all compounds were determined by elemental analysis. Conclusion: Antibacterial activity of the derivatives was examined for the synthesized compounds and results indicate that compound with bromine substitution has a good activity profile.

scholarly journals Bioactive Ascochlorin Analogues from the Marine-Derived Fungus Stilbella fimetaria

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 46
Author(s):  
Karolina Subko ◽  
Sara Kildgaard ◽  
Francisca Vicente ◽  
Fernando Reyes ◽  
Olga Genilloud ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antifungal Activity ◽  
2D Nmr ◽  
Bioactive Metabolites ◽  
Double Bonds ◽  
Relative Configuration ◽  
D 23 ◽  
Fungal Extracts

The marine-derived fungus Stilbella fimetaria is a chemically talented fungus producing several classes of bioactive metabolites, including meroterpenoids of the ascochlorin family. The targeted dereplication of fungal extracts by UHPLC-DAD-QTOF-MS revealed the presence of several new along with multiple known ascochlorin analogues (19–22). Their structures and relative configuration were characterized by 1D and 2D NMR. Further targeted dereplication based on a novel 1,4-benzoquinone sesquiterpene derivative, fimetarin A (22), resulted in the identification of three additional fimetarin analogues, fimetarins B–D (23–25), with their tentative structures proposed from detailed MS/HRMS analysis. In total, four new and eight known ascochlorin/fimetarin analogues were tested for their antimicrobial activity, identifying the analogues with a 5-chloroorcylaldehyde moiety to be more active than the benzoquinone analogue. Additionally, the presence of two conjugated double bonds at C-2′/C-3′ and C-4′/C-5′ were found to be essential for the observed antifungal activity, whereas the single, untailored bonds at C-4′/C-5′ and C-8′/C-9′ were suggested to be necessary for the observed antibacterial activity.

scholarly journals An In Vitro Study on the Antimicrobial Properties of Essential Oil Modified Resin Composite against Oral Pathogens

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Antimicrobial Agents ◽  
Resin Composite ◽  
Antimicrobial Properties ◽  
In Vitro Study ◽  
Diffusion Method ◽  
Oral Pathogens

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.

scholarly journals Pseudomonas sp. COW3 Produces New Bananamide-Type Cyclic Lipopeptides with Antimicrobial Activity against Pythium myriotylum and Pyricularia oryzae

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4170 ◽  
Author(s):  
Olumide Owolabi Omoboye ◽  
Niels Geudens ◽  
Matthieu Duban ◽  
Mickaël Chevalier ◽  
Christophe Flahaut ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Genome Mining ◽  
Antagonistic Activity ◽  
Pyricularia Oryzae ◽  
Pseudomonas Sp ◽  
Pythium Myriotylum ◽  
Cyclic Lipopeptides ◽  
Peptide Synthetase ◽  
Kendrick Mass Defect

Pseudomonas species are metabolically robust, with capacity to produce secondary metabolites including cyclic lipopeptides (CLPs). Herein we conducted a chemical analysis of a crude CLP extract from the cocoyam rhizosphere-derived biocontrol strain Pseudomonas sp. COW3. We performed in silico analyses on its whole genome, and conducted in vitro antagonistic assay using the strain and purified CLPs. Via LC-MS and NMR, we elucidated the structures of four novel members of the bananamide group, named bananamides D-G. Besides variability in fatty acid length, bananamides D-G differ from previously described bananamides A-C and MD-0066 by the presence of a serine and aspartic acid at position 6 and 2, respectively. In addition, bananamide G has valine instead of isoleucine at position 8. Kendrick mass defect (KMD) allowed the assignment of molecular formulae to bananamides D and E. We unraveled a non-ribosomal peptide synthetase cluster banA, banB and banC which encodes the novel bananamide derivatives. Furthermore, COW3 displayed antagonistic activity and mycophagy against Pythium myriotylum, while it mainly showed mycophagy on Pyricularia oryzae. Purified bananamides D-G inhibited the growth of P. myriotylum and P. oryzae and caused hyphal distortion. Our study shows the complementarity of chemical analyses and genome mining in the discovery and elucidation of novel CLPs. In addition, structurally diverse bananamides differ in their antimicrobial activity.

Antimicrobial Activity of Isopteropodine

2005 ◽  
Vol 60 (5-6) ◽  
pp. 385-388 ◽  
Author(s):  
Rubén García ◽  
Cesia Cayunao ◽  
Ronny Bocic ◽  
Nadine Backhouse ◽  
Carla Delporte ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Gram Positive ◽  
Uncaria Tomentosa ◽  
Gram Positive Bacteria

Bioassay-directed fractionation for the determination of antimicrobial activity of Uncaria tomentosa, has led to the isolation of isopteropodine (0.3%), a known Uncaria pentacyclic oxindol alkaloid that exhibited antibacterial activity against Gram positive bacteria.

scholarly journals Genetic Analysis of Colistin Resistance in Salmonella enterica Serovar Typhimurium

2009 ◽  
Vol 53 (6) ◽  
pp. 2298-2305 ◽  
Author(s):  
Song Sun ◽  
Aurel Negrea ◽  
Mikael Rhen ◽  
Dan I. Andersson
Keyword(s):  
Mutation Rate ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Regulatory System ◽  
Clinical Settings ◽  
Missense Mutations ◽  
Regulator Protein ◽  
Serovar Typhimurium ◽  
Sensor Kinases ◽  
Genes Encoding

ABSTRACT Colistin is a cyclic cationic peptide that kills gram-negative bacteria by interacting with and disrupting the outer membrane. We isolated 44 independent mutants in Salmonella enterica serovar Typhimurium with reduced susceptibility to colistin and identified 27 different missense mutations located in the pmrA and pmrB genes (encoding the regulator and sensor of a two-component regulatory system) that conferred increased resistance. By comparison of the two homologous sensor kinases, PmrB and EnvZ, the 22 missense mutations identified in pmrB were shown to be located in four different structural domains of the protein. All five pmrA mutations were located in the phosphate receiver domain of the regulator protein. The mutants appeared at a mutation rate of 0.6 × 10−6 per cell per generation. The MICs of colistin for the mutants increased 2- to 35-fold, and the extent of killing was reduced several orders of magnitude compared to the susceptible strain. The growth rates of the mutants were slightly reduced in both rich medium and M9-glycerol minimal medium, whereas growth in mice appeared unaffected by the pmrA and pmrB mutations. The low fitness costs and the high mutation rate suggest that mutants with reduced susceptibility to colistin could emerge in clinical settings.

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