Identification of Antibacterial Peptides from Bovine κ-Casein

2006 ◽  
Vol 69 (12) ◽  
pp. 2992-2997 ◽  
Author(s):  
IVÁN LÓPEZ-EXPÓSITO ◽  
FABIO MINERVINI ◽  
LOURDES AMIGO ◽  
ISIDRA RECIO
Keyword(s):  
High Performance ◽  
Antibacterial Effect ◽  
Amino Acid Sequences ◽  
Listeria Innocua ◽  
Tandem Mass ◽  
Gram Negative Bacteria ◽  
Antibacterial Peptides ◽  
Antibacterial Effects ◽  
Gram Negative ◽  
Active Peptides

The objective of the present study was to identify antimicrobial peptides present in several digests of commercial caseins with gastric enzymes. The most active hydrolysate against Escherichia coli ATCC 25922 and Listeria innocua CECT 910T corresponded to a pepsin digest of bovine κ-casein. The protein digest was first separated by semipreparative high-performance liquid chromatography (HPLC), and the most active fractions were again subjected to a second chromatographic step. Finally, identification of the active peptides was carried out by online and offline HPLC–electrospray ionization–tandem mass spectrometry. By means of this technique, 21 peptides were identified in the active HPLC fractions. Although most were derived from bovine κ-casein, some of the identified fragments corresponded to β-casein and αs-casein fragments, a result of the presence of small amounts of these proteins in the preparation of κ-casein. Some of the peptides identified were chemically synthesized and showed antibacterial effects against several gram-positive and gram-negative bacteria. Among the synthesized peptides, κ-casein f(18–24), f(30–32), and f(139–146) were most effective against all bacteria tested. The antibacterial effect of these peptides is discussed in relation to their amino acid sequences.

scholarly journals The tridecaptins: non-ribosomal peptides that selectively target Gram-negative bacteria

2021 ◽  
Author(s):  
Samantha J. Bann ◽  
Ross D. Ballantine ◽  
Stephen A. Cochrane
Keyword(s):  
Gram Negative Bacteria ◽  
Antibacterial Peptides ◽  
Gram Negative ◽  
Non Ribosomal Peptides

Tridecaptins are a re-emerging class of non-ribosomal antibacterial peptides (NRAPs) with potent activity against highly problematic strains of Gram-negative bacteria.

scholarly journals Antibacterial activity of plant extracts against Listeria monocytogenes isolated from ready-to-eat salads

2020 ◽  
Vol 13 (1) ◽  
pp. 131-143
Author(s):  
É. György ◽  
É. Laslo ◽  
E. Csató
Keyword(s):  
Listeria Monocytogenes ◽  
Essential Oils ◽  
Antibacterial Effect ◽  
Storage Conditions ◽  
Inhibitory Effect ◽  
Listeria Innocua ◽  
Foodborne Diseases ◽  
Bacterial Strains ◽  
Antibacterial Effects ◽  
Growth Environment

Abstract Ready-to-eat salads are becoming more and more popular. However, due to their ingredients, they represent a suitable growth environment for different microbes. In the prevention of foodborne diseases, hygienic food preparation and appropriate storage conditions are very important. During this study, ten different ready-to-eat salads were analysed for the presence of Listeria monocytogenes. Five different selective agar mediums were used for the enumeration and isolation of Listeria monocytogenes. The isolated bacterial strains were subjected to morphological and biochemical confirmation tests. The antibacterial effects of five different freshly squeezed vegetable juices (carrots, celery, beets, horseradish, and onions) and of five essential oils (dill, thyme, oregano, lemongrass, and sage) were determined against Listeria monocytogenes, Listeria innocua, and L. monocytogenes strains isolated from ready-to-eat salads. Based on the results obtained from fresh vegetable juices, carrot juice exerted the highest antibacterial effect, while the others showed no or slight inhibitory effect (horseradish, beets, onions) against Listeria species. Among the essential oils, thyme, lemongrass, and oregano showed the strongest antibacterial effect against the studied Listeria species.

scholarly journals Antimicrobial functional divergence of the cecropin antibacterial peptide gene family in Musca domestica

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Jian Peng ◽  
Zhaoying Wu ◽  
Weiwei Liu ◽  
Huiling Long ◽  
Guiming Zhu ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Musca Domestica ◽  
Morphological Changes ◽  
Functional Divergence ◽  
Membrane Integrity ◽  
Gram Negative Bacteria ◽  
Dependent Manner ◽  
Antibacterial Effects ◽  
Gram Negative ◽  
Absorbing Material

Abstract Background It has been reported that there are more than ten antimicrobial peptides (AMPs) belonging to the cecropin family in Musca domestica; however, few of them have been identified, and the functions of the other molecules are poorly understood. Methods Sequences of the M. domestica cecropin family of genes were cloned from cDNA template, which was reverse-transcribed from total mRNA isolated from third-instar larvae of M. domestica that were challenged with pathogens. Sequence analysis was performed using DNAMAN comprehensive analysis software, and a molecular phylogenetic tree of the cecropin family was constructed using the Neighbour-Joining method in MEGA v.5.0 according to the mature peptide sequences. Antibacterial activity of the synthetic M. domestica cecropin protein was detected and the minimum inhibitory concentration (MIC) values were determined using broth microdilution techniques. Time-killing assays were performed on the Gram-negative bacteria, Acinetobacter baumannii, at the logarithmic or stabilizing stages of growth, and its morphological changes when treated with Cec4 were assessed by scanning electron microscopy (SEM) and detection of leakage of 260 nm absorbing material. Results Eleven cecropin family genes, namely Cec01, Cec02 and Cec1-9, show homology to the Cec form in a multigene family on the Scaffold18749 of M. domestica. In comparing the encoded cecropin protein sequences, most of them have the basic characteristics of the cecropin family, containing 19 conservative amino acid residues. To our knowledge, this is the first experimental demonstration that most genes in the Cec family are functional. Cec02, Cec1, Cec2, Cec5 and Cec7 have similar antibacterial spectra and antibacterial effects against Gram-negative bacteria, while Cec4 displays a more broad-spectrum of antimicrobial activity and has a very strong effect on A. baumannii. Cec4 eliminated A. baumannii in a rapid and concentration-dependent manner, with antibacterial effects within 24 h at 1× MIC and 2× MIC. Furthermore, SEM analysis and the leakage of 260 nm absorbing material detection indicated that Cec4 sterilized the bacteria through the disruption of cell membrane integrity. Conclusions Although there are more than ten cecropin genes related to M. domestica, some of them have no preferred antibacterial activity other than Cec4 against A. baumannii.

scholarly journals The ColM Family, Polymorphic Toxins Breaching the Bacterial Cell Wall

mBio ◽  
2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Maarten G. K. Ghequire ◽  
Susan K. Buchanan ◽  
René De Mot
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Cytoplasmic Membrane ◽  
Catalytic Domain ◽  
Gram Negative Bacteria ◽  
Antibacterial Peptides ◽  
Gram Negative ◽  
Lipid Ii ◽  
Associated Proteins ◽  
Colicin M

ABSTRACT Bacteria host an arsenal of antagonism-mediating molecules to combat for ecologic space. Bacteriocins represent a pivotal group of secreted antibacterial peptides and proteins assisting in this fight, mainly eliminating relatives. Colicin M, a model for peptidoglycan-interfering bacteriocins in Gram-negative bacteria, appears to be part of a set of polymorphic toxins equipped with such a catalytic domain (ColM) targeting lipid II. Diversifying recombination has enabled parasitism of different receptors and has also given rise to hybrid bacteriocins in which ColM is associated with another toxin module. Remarkably, ColM toxins have recruited a diverse array of immunity partners, comprising cytoplasmic membrane-associated proteins with different topologies. Together, these findings suggest that different immunity mechanisms have evolved for ColM, in contrast to bacteriocins with nuclease activities.

scholarly journals A Study on Antibacterial Activity of Silver Nanoparticles

2018 ◽  
Vol 29 (2) ◽  
pp. 37-41
Author(s):  
M Iqbal Hossain ◽  
M Anwar Habib ◽  
Nazimuddin Ahmed
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Antibacterial Effect ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Disc Diffusion ◽  
Disc Diffusion Method ◽  
Reference Drug ◽  
Gram Negative ◽  
Quasi Experimental

This quasi experimental study was designed to evaluate antibacterial activity of chemically synthesized silver nanoparticles (AgNPs) from silver nitrate (AgNO3) solutions on gram negative bacteria like E.Coli using disc diffusion method. Different concentrations of AgNPs, AgNO3 and reference drug ciprofloxacin were used to find out the antibacterial activity which revealed that AgNPs possessed significant antibacterial effect compared to AgNO3 solutions but relatively less antibacterial effect than that of ciprofloxacin. So chemical synthesis guided AgNPs may have some antibacterial effects.TAJ 2016; 29(2): 37-41

scholarly journals Characterization and Evaluation The Biological Activity of Prepared Nano-Gentamicin Nanoparticles

2021 ◽  
Vol 910 (1) ◽  
pp. 012078
Author(s):  
Rana A. Kamal ◽  
Quraish A. Kahdhum ◽  
Awatif I. Mohammed ◽  
Ahmed J. Essa ◽  
Maan A. Abd elhamid ◽  
...  
Keyword(s):  
Biological Activity ◽  
Antibacterial Effect ◽  
Sol Gel ◽  
Veterinary Drug ◽  
Homogeneous Distribution ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Force Microscopy ◽  
Average Size

Abstract Nanotechnology is a capable approach to enhance the activity of common antimicrobial agent mainly used in human and veterinary drug. Gentamycin is a broad-spectrum antibacterial against Gram-positive and Gram-negative bacteria. The study aims to determine the characterization and the biological activity of gentamicin in the Nano-form prepared by Sol-gel application using an ultrasound device by aqueous solution at temperature (80)0C. Nano gentamycin examined by Scanning electron microscopy (SEM), transmission (TEM), atomic force microscopy (AFM) and antibacterial effect of both Nano and stander gentamycin were analyzed. The results showed that the average size of gentamycin nanoparticles was 68.51 nanometers with homogeneous distribution. The EDX showed large number of elements present in the Nano solution. The antibacterial effect of Nano gentamycin took a wide inhibition range of Gram-positive and Gram-negative bacteria compared to the standard substance, where the inhibition diameter for E.coli was 29 mm, and for St. epidermidis was 27 mm. The MIC of gentamicin nanostructures was the concentration 0.00125 mg/ml.

scholarly journals Antibacterial Peptides

Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 142
Author(s):  
Jean-Marc Sabatier
Keyword(s):  
Antimicrobial Peptides ◽  
Host Defense ◽  
Life Forms ◽  
Natural Host ◽  
Gram Negative Bacteria ◽  
Antibacterial Peptides ◽  
Chemotherapeutic Drugs ◽  
Gram Positive ◽  
Defense Compounds ◽  
Gram Negative

As natural host defense compounds produced by numerous prokaryotic and eukaryotic life forms, antimicrobial peptides (AMPs) are now emerging as solid candidate chemotherapeutic drugs to fight against the various types of pathogenic Gram-positive and Gram-negative bacteria, especially those resistant to current antibiotics [...]

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