Identification of Ly2 members as antimicrobial peptides from zebrafish Danio rerio

The emergence of multidrug-resistant (MDR) microbes caused by overuse of antibiotics leads to urgent demands for novel antibiotics exploration. Our recent data showed that Ly2.1–3 (a novel lymphocyte antigen 6 (Ly6) gene cluster) were proteins with cationic nature and rich in cysteine content, that are characteristic of antimicrobial peptides (AMPs) and their expression were all significantly up-regulated after challenge with lipopolysaccharide (LPS). These strongly suggested that Ly2.1–3 are potential AMPs, but firm evidence are lacking. Here, we clearly showed that the recombinant proteins of Ly2.1–3 were capable of killing Gram-negative bacteria Aeromonas hydrophila and Escherichia coli, while they had little bactericidal activity against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis. We also showed that recombinant proteins Ly2.1–3 (rLy2.1–3) were able to bind to the Gram-negative bacteria A. hydrophila, E. coli and the microbial signature molecule LPS, but not to the Gram-positive bacteria S. aureus and B. subtilis as well as the microbial signature molecule LTA. Moreover, the Scatchard analysis revealed that rLy2.1–3 could specifically bind to LPS. Finally, we found that Ly2.1–3 were not cytotoxic to mammalian cells. All these together indicate that Ly2.1–3 can function as AMPs.

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Water-dispersible glycosylated poly(2,5′-thienylene)porphyrin-based nanoparticles for antibacterial photodynamic therapy

Photochemical & Photobiological Sciences ◽

10.1039/c8pp00470f ◽

2019 ◽

Vol 18 (5) ◽

pp. 1147-1155 ◽

Cited By ~ 5

Author(s):

Rehan Khan ◽

Melis Özkan ◽

Aisan Khaligh ◽

Dönüs Tuncel

Keyword(s):

Antibacterial Activity ◽

Photodynamic Therapy ◽

Singlet Oxygen ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Water Dispersible ◽

Gram Positive Bacteria ◽

High Yields

Water-dispersible glycosylated poly(2,5′-thienylene)porphyrin-based nanoparticles have the ability to generate singlet oxygen in high yields and exhibit light-triggered antibacterial activity against Gram negative bacteria, E. coli as well as Gram positive bacteria, B. subtilis.

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Synthesis and Antibacterial Activity of Chalcones and Pyrimidine-2-ones

E-Journal of Chemistry ◽

10.1155/2005/134830 ◽

2005 ◽

Vol 2 (2) ◽

pp. 109-112

Author(s):

A. K. Parekh ◽

K. K. Desai

Keyword(s):

Antibacterial Activity ◽

Spectral Data ◽

Elemental Analysis ◽

Aromatic Aldehydes ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria ◽

H Nmr

Some new chalcones have been prepared by Claisen-schmidt condensation of ketone and different aromatic aldehydes. These chalcones on condensation with urea in presence of acid gave Pyrimidine-2-ones. The synthesized compounds have been characterized by elemental analysis, IR and1H NMR spectral data. They have been screened for their antibacterial activity against Gram positive bacteria B. subtillis & S. aureus and Gram negative bacteria E. coli & S. typhi.

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Physicochemical Properties That Enhance Discriminative Antibacterial Activity of Short Dermaseptin Derivatives

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00030-06 ◽

2006 ◽

Vol 50 (8) ◽

pp. 2666-2672 ◽

Cited By ~ 27

Author(s):

Shahar Rotem ◽

Inna Radzishevsky ◽

Amram Mor

Keyword(s):

Antimicrobial Peptides ◽

Physicochemical Properties ◽

Culture Media ◽

Gram Negative Bacteria ◽

Terminal Sequence ◽

Binding Properties ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Cytoplasmic Membranes

ABSTRACT Antimicrobial peptides are widely believed to exert their effects by nonspecific mechanisms. We assessed the extent to which physicochemical properties can be exploited to promote discriminative activity by manipulating the N-terminal sequence of the 13-mer dermaseptin derivative K4-S4(1-13) (P). Inhibitory activity determined in culture media against 16 strains of bacteria showed that when its hydrophobicity and charge were changed, P became predominantly active against either gram-positive or gram-negative bacteria. Thus, conjugation of various aminoacyl-lysin moieties (e.g., aminohexyl-K-P) led to inactivity against gram-positive bacteria (MIC50 > 50 μM) but potent activity against gram-negative bacteria (MIC50, 6.2 μM). Conversely, conjugation of equivalent acyls to the substituted analog M4-S4(1-13) (e.g., hexyl-M4-P) led to inactivity against gram-negative bacteria (MIC50 > 50 μM) but potent activity against gram-positive bacteria (MIC50, 3.1 μM). Surface plasmon resonance experiments, used to investigate peptides' binding properties to lipopolysaccharide-containing idealized phospholipid membranes, suggest that although the acylated derivatives have increased lipophilic properties with parallel antibacterial behavior, hydrophobic derivatives are prevented from reaching the cytoplasmic membranes of gram-negative bacteria. Moreover, unlike modifications that enhanced the activity against gram-positive bacteria, which also enhanced hemolysis, we found that modifications that enhanced activity against gram-negative bacteria generally reduced hemolysis. Thus, compared with the clinically tested peptides MSI-78 and IB-367, the dermaseptin derivative aminohexyl-K-P performed similarly in terms of potency and bactericidal kinetics but was significantly more selective in terms of discrimination between bacteria and human erythrocytes. Overall, the data suggest that similar strategies maybe useful to derive potent and safe compounds from known antimicrobial peptides.

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Novel Chitosan Polymer Design, Synthesis Using Mentha piperita of ZnO NPs as a Catalyst: Antibacterial Evaluation against Gram-Negative Multidrug-Resistant Pathogens

Journal of Nanomaterials ◽

10.1155/2021/8804837 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Ponnusamy Packialakshmi ◽

Perumal Gobinath ◽

Daoud Ali ◽

Saud Alarifi ◽

Balasubramani Ravindran ◽

...

Keyword(s):

Multidrug Resistant ◽

High Yield ◽

Mentha Piperita ◽

Resonance Spectroscopy ◽

Gram Negative Bacteria ◽

Zno Nps ◽

Gram Positive ◽

Gram Negative ◽

Chitosan Derivatives ◽

Gram Positive Bacteria

The goal of this research is to create a novel Schiff base of chitosan polymer derivatives 1a-1j. Nanotechnology is a promising field since it avoids the usage of hazardous chemicals while also saving time. Using the leaf extract of the pharmacologically valuable herb Mentha piperita, we described a green synthesis of ZnO NPs. Zinc oxide ions may be easily reduced into ZnO NPs using a Mentha piperita extract. ZnO NPs were employed as a phytocatalyst in this investigation to make chitosan derivatives. The synthetic procedure is straightforward, with a short reaction time and a high yield. Our newly synthesized compounds have been characterized by FTIR and nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR), and morphology analysis was observed by XRD, SEM, and TEM. In addition, the antibacterial activity was also evaluated against gram-positive bacteria and gram-negative bacteria. Compound 1b is extremely active against gram-negative bacteria (4.0 μg/mL, E. coli), and compound 1h is highly active against gram-positive bacteria (6.0 μg/mL, S. aureus) compared with standard erythromycin and other chitosan derivatives. As a result, compounds 1b and 1h could be a high crucial molecule in the development of antibacterial drugs.

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In VitroAntimicrobial Activity and Effect on Biofilm Production of a White Grape Juice (Vitis vinifera) Extract

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2015/856243 ◽

2015 ◽

Vol 2015 ◽

pp. 1-5 ◽

Cited By ~ 15

Author(s):

Angela Filocamo ◽

Carlo Bisignano ◽

Giuseppina Mandalari ◽

Michele Navarra

Keyword(s):

Aspergillus Niger ◽

Grape Juice ◽

Antimicrobial Effect ◽

Gram Negative Bacteria ◽

Respiratory Pathogens ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria

Background. The aim of the present study was to evaluate the antimicrobial effect of a white grape juice extract (WGJe) against a range of Gram-positive and Gram-negative bacteria, yeasts, and the fungusAspergillus niger. WGJe was also tested on the production of bacterial biofilmsin vitro.Results. WGJe inhibitedin vitromost Gram-positive bacteria tested,Staphylococcus aureusATCC 6538P being the most sensitive strain (MIC values of 3.9 μg/mL). The effect was bactericidal at the concentration of 500 μg/mL. Amongst the Gram-negative bacteria,Escherichia coliwas the only susceptible strain (MIC and MBC of 2000 μg/mL). No effect on the growth ofCandidasp. and the fungusAspergillus nigerwas detected (MIC values > 2000 μg/mL). WGJe inhibited the biofilms formation ofE. coliandPseudomonas aeruginosawith a dose-dependent effect.Conclusions. WGJe exerted both bacteriostatic and bactericidal activityin vitro. The presented results could be used to develop novel strategies for the treatment of skin infections and against potential respiratory pathogens.

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Antimicrobial Peptide Resistance Genes in the Plant Pathogen Dickeya dadantii

Applied and Environmental Microbiology ◽

10.1128/aem.01757-16 ◽

2016 ◽

Vol 82 (21) ◽

pp. 6423-6430 ◽

Cited By ~ 7

Author(s):

Caroline Pandin ◽

Martine Caroff ◽

Guy Condemine

Keyword(s):

Antimicrobial Peptides ◽

Bacterial Resistance ◽

Soft Rot ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Dickeya Dadantii ◽

Gram Negative ◽

Content Type ◽

Gram Positive Bacteria ◽

New Genes

ABSTRACTModification of teichoic acid through the incorporation ofd-alanine confers resistance in Gram-positive bacteria to antimicrobial peptides (AMPs). This process involves the products of thedltXABCDgenes. These genes are widespread in Gram-positive bacteria, and they are also found in a few Gram-negative bacteria. Notably, these genes are present in all soft-rot enterobacteria (PectobacteriumandDickeya) whosedltDXBACoperons have been sequenced. We studied the function and regulation of these genes inDickeya dadantii.dltBexpression was induced in the presence of the AMP polymyxin. It was not regulated by PhoP, which controls the expression of some genes involved in AMP resistance, but was regulated by ArcA, which has been identified as an activator of genes involved in AMP resistance. However,arcAwas not the regulator responsible for polymyxin induction of these genes in this bacterium, which underlines the complexity of the mechanisms controlling AMP resistance inD. dadantii. Two other genes involved in resistance to AMPs have also been characterized,phoSandphoH.dltB,phoS,phoH, andarcAbut notdltDmutants were more sensitive to polymyxin than the wild-type strain. Decreased fitness of thedltB,phoS, andphoHmutants in chicory leaves indicates that their products are important for resistance to plant AMPs.IMPORTANCEGram-negative bacteria can modify their lipopolysaccharides (LPSs) to resist antimicrobial peptides (AMPs). Soft-rot enterobacteria (DickeyaandPectobacteriumspp.) possess homologues of thedltgenes in their genomes which, in Gram-positive bacteria, are involved in resistance to AMPs. In this study, we show that these genes confer resistance to AMPs, probably by modifying LPSs, and that they are required for the fitness of the bacteria during plant infection. Two other new genes involved in resistance were also analyzed. These results show that bacterial resistance to AMPs can occur in bacteria through many different mechanisms that need to be characterized.

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NonToxic Silver/Poly-1-Vinyl-1,2,4-Triazole Nanocomposite Materials with Antibacterial Activity

Nanomaterials ◽

10.3390/nano10081477 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1477 ◽

Cited By ~ 2

Author(s):

Irina A. Shurygina ◽

Galina F. Prozorova ◽

Irina S. Trukhan ◽

Svetlana A. Korzhova ◽

Tatiana V. Fadeeva ◽

...

Keyword(s):

Antibacterial Activity ◽

Mammalian Cells ◽

Antimicrobial Properties ◽

Fibroblast Cell ◽

Nanocomposite Materials ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Fibroblast Cell Culture

Novel silver/poly-1-vinyl-1,2,4-triazole nanocomposite materials—possessing antimicrobial activity against Gram-positive and Gram-negative bacteria—have been synthesized and characterized in the solid state and aqueous solution by complex of modern physical-chemical and biologic methods. TEM-monitoring has revealed the main stages of microbial cell (E. coli) destruction by novel nanocomposite. The concept of direct polarized destruction of microbes by nanosilver proposed by the authors allows the relationship between physicochemical and antimicrobial properties of novel nanocomposites. At the same time, it was shown that the nanocomposite was nontoxic to the fibroblast cell culture. Thus, the synthesized nanocomposite combining antibacterial activity against Gram-positive and Gram-negative bacteria as well as the absence of toxic effects on mammalian cells is a promising material for the development of catheters, coatings for medical devices.

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Inhibition of Multidrug-Resistant Gram-Positive and Gram-Negative Bacteria by a Photoactivated Porphyrin

Polish Journal of Microbiology ◽

10.5604/01.3001.0010.7092 ◽

2017 ◽

Vol 66 (4) ◽

pp. 533-536 ◽

Cited By ~ 2

Author(s):

Moreno Bondi ◽

Anna Mazzini ◽

Simona de Niederhäusern ◽

Ramona Iseppi ◽

Patrizia Messi

Keyword(s):

Multidrug Resistant ◽

Resistant Bacteria ◽

Gram Negative Bacteria ◽

Multidrug Resistant Bacteria ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

In Vitro Antibacterial Activity

The authors studied the in vitro antibacterial activity of the photo-activated porphyrin meso-tri(N-methyl-pyridyl), mono(N-tetradecyl-pyridyl)porphine (C14) against four multidrug-resistant bacteria: Staphylococcus aureus, Enterococcus faecalis (Gram-positive), Escherichia coli, Pseudomonas aeruginosa (Gram-negative). Using 10 μg/ml of porphyrin and 60 sec irradiation we observed the remarkable susceptibility of S. aureus and E. faecalis to treatment while, under the same conditions, E. coli and P. aeruginosa showed very low susceptibility. In a later stage, suspensions of Gram-negative bacteria were processed with EDTA before photo-activation, obtaining a significant decrease in viable counts. In view of the results, if the combination of low porphyrin concentrations and short irradiation times will be effective in vivo also, this approach could be a possible alternative to antibiotics, in particular against localized infections due to multidrug-resistant microorganisms.

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Bacteriological Profile of Tracheal Aspirates of the Patients Attending Neuro-hospital Nepal

International Journal of Life Sciences ◽

10.3126/ijls.v4i0.3496 ◽

2010 ◽

Vol 4 ◽

Cited By ~ 3

Author(s):

Pratirodh Koirala ◽

Dwij Raj Bhatta ◽

Prakash Ghimire ◽

Bharat Mani Pokhrel ◽

Upendra Devkota

Keyword(s):

Pseudomonas Aeruginosa ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Gram Negative Bacteria ◽

Viridans Streptococci ◽

Multidrug Resistant Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Tracheal Aspirates

The tracheostomized patients are colonized mostly by gram negative bacteria which lead to either tracheobronchitis or bronchopneumonia. This study was conducted to isolate and identify the potential pathogen causing post tracheostomy infection. A cross-sectional study was conducted during April 2008 to February 2009 based at Neuro Center, Kathmandu. Tracheal aspirates of 50 patients having fever more than 38°C were collected and analyzed for bacterial content. Out of the 50 cases, 45(90%) cases showed bacterial growth. Sixty-seven isolates were identified; with 20(44.4%) poly-microbial cases. Pseudomonas aeruginosa and enteric gram negative bacteria were predominant bacteria (n=27, 40.3%) followed by Staphylococcus aureus (n=7, 10.4%), other Gram negative bacteria (n=4, 5.9%) and Viridans Streptococci (n=2, 2.9%). Pseudomonas aeruginosa were most sensitive to the Amikacin (n=22, 81.4%) and Ciprofloxacin (n=19, 70.3%). All Pseudomonal isolates were resistant to the Cefotaxime. Enteric Gram Negative bacteria (EGNB) were most sensitive to Amikacin and Chloramphenicol (20, 74.0%) and all were resistant to Ampicillin and Cephalexin. All the gram positive bacteria isolated were sensitive to Vancomycin. Among the total isolates, 24 (88.8%) of Pseudomonas aeruginosa, 21 (66.6%) of enteric gram negative bacteria, and 5 (55.5%) of Gram positive bacteria were multidrug resistant (MDR). The study reported alarming condition of MDR in tracheal aspirates. So surveillance for source of multidrug resistant bacteria would be beneficial for intervention of infection related to it. Key words: Tracheal aspirates, polymicrobial growth, Multidrug resistant bacteria (MDR)10.3126/ijls.v4i0.3496International Journal of Life Sciences Vol.4 2010 pp.60-65

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A Short Peptide Derived from the ZorO Toxin Functions as an Effective Antimicrobial

Toxins ◽

10.3390/toxins11070392 ◽

2019 ◽

Vol 11 (7) ◽

pp. 392 ◽

Cited By ~ 1

Author(s):

Otsuka ◽

Ishikawa ◽

Takahashi ◽

Masuda

Keyword(s):

Amino Acids ◽

Antimicrobial Peptides ◽

Mammalian Cells ◽

Membrane Damage ◽

Type I ◽

Gram Positive ◽

Short Peptide ◽

E Coli ◽

Gram Positive Bacteria ◽

Endogenous Expression

Antimicrobial peptides are potential molecules for the development of novel antibiotic agents. The ZorO toxin of a type I toxin–antitoxin system in Escherichia coli O157:H7 is composed of 29 amino acids and its endogenous expression inhibits E. coli growth. However, little is known about its inhibitory mechanism. In this study, we demonstrate that the ZorO localized in the inner membrane affects the plasma membrane integrity and potential when expressed in E. coli cells, which triggers the production of cytotoxic hydroxyl radicals. We further show that five internal amino acids (Ala–Leu–Leu–Arg–Leu; ALLRL) of ZorO are necessary for its toxicity. This result prompted us to address the potential of the synthetic ALLRL peptide as an antimicrobial. Exogenously-added ALLRL peptide to Gram-positive bacteria, Staphylococcus aureus and Bacillus subtilis, and a fungus, Candida albicans, trigger cell membrane damage and exhibit growth defect, while having no effect on Gram-negative bacterium, E. coli. The ALLRL peptide retains its activity under the physiological salt concentrations, which is in contrast to natural antimicrobial peptides. Importantly, this peptide has no toxicity against mammalian cells. Taken together, an effective and short peptide, ALLRL, would be an attractive antimicrobial to Gram-positive bacteria and C. albicans.

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