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 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 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 [...]

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 Novel inducible antibacterial peptides from a hemipteran insect, the sap-sucking bug Pyrrhocoris apterus

1994 ◽  
Vol 300 (2) ◽  
pp. 567-575 ◽  
Author(s):  
S Cociancich ◽  
A Dupont ◽  
G Hegy ◽  
R Lanot ◽  
F Holder ◽  
...  
Keyword(s):  
Antibacterial Peptide ◽  
Gram Negative Bacteria ◽  
Antibacterial Peptides ◽  
Pyrrhocoris Apterus ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Rich Domain ◽  
Representative Species ◽  
Hemipteran Insect ◽  
Proline Rich Peptide

Insects belonging to the recent orders of the endopterygote clade (Lepidoptera, Diptera, Hymenoptera and Coleoptera) respond to bacterial challenge by the rapid and transient synthesis of a battery of potent antibacterial peptides which are secreted into their haemolymph. Here we present the first report on inducible antibacterial molecules in the sap-sucking bug Pyrrhocoris apterus, a representative species of the Hemiptera, which predated the Endoptergotes by at least 50 million years in evolution. We have isolated and characterized from immune blood of this species three novel peptides or polypeptides: (i) a 43-residue cysteine-rich anti-(Gram-positive bacteria) peptide which is a new member of the family of insect defensins; (ii) a 20-residue proline-rich peptide carrying an O-glycosylated substitution (N-acetylgalactosamine), active against Gram-negative bacteria; (iii) a 133-residue glycine-rich polypeptide also active against Gram-negative bacteria. The proline-rich peptide shows high sequence similarities with drosocin, an O-glycosylated antibacterial peptide from Drosophila, and also with the N-terminal domain of diptericin, an inducible 9 kDa antibacterial peptide from members of the order Diptera, whereas the glycine-rich peptide has similarities with the glycine-rich domain of diptericin. We discuss the evolutionary aspects of these findings.

scholarly journals Human Peptidoglycan Recognition Proteins Require Zinc to Kill Both Gram-Positive and Gram-Negative Bacteria and Are Synergistic with Antibacterial Peptides

2007 ◽  
Vol 178 (5) ◽  
pp. 3116-3125 ◽  
Author(s):  
Minhui Wang ◽  
Li-Hui Liu ◽  
Shiyong Wang ◽  
Xinna Li ◽  
Xiaofeng Lu ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Antibacterial Peptides ◽  
Gram Positive ◽  
Gram Negative

Bacterial-Mucosal Cell Junctional Complexes

1974 ◽  
Vol 32 ◽  
pp. 144-145
Author(s):  
Roger C. Wagner
Keyword(s):  
Intestinal Wall ◽  
Rat Colon ◽  
Mucosal Cell ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Mucosal Cells ◽  
Mucosal Lining ◽  
Degenerative Alterations ◽  
Junctional Complexes ◽  
Intestinal Mucosal Cells

Bacteria exhibit the ability to adhere to the apical surfaces of intestinal mucosal cells. These attachments either precede invasion of the intestinal wall by the bacteria with accompanying inflammation and degeneration of the mucosa or represent permanent anchoring sites where the bacteria never totally penetrate the mucosal cells.Endemic gram negative bacteria were found attached to the surface of mucosal cells lining the walls of crypts in the rat colon. The bacteria did not intrude deeper than 0.5 urn into the mucosal cells and no degenerative alterations were detectable in the mucosal lining.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

Ultrastructure of periplasmic bodies in gram-negative bacteria

1990 ◽  
Vol 48 (3) ◽  
pp. 640-641
Author(s):  
Xie Nianming ◽  
Ding Shaoqing ◽  
Wang Luping ◽  
Yuan Zenglin ◽  
Zhan Guolai ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Campylobacter Jejuni ◽  
Proteus Mirabilis ◽  
Shigella Flexneri ◽  
Morphological Description ◽  
Gram Negative Bacteria ◽  
Periplasmic Space ◽  
Clostridium Tetani ◽  
Gram Negative ◽  
Brucella Canis

Perhaps the data about periplasmic enzymes are obtained through biochemical methods but lack of morphological description. We have proved the existence of periplasmic bodies by electron microscope and described their ultrastructures. We hope this report may draw the attention of biochemists and mrophologists to collaborate on researches in periplasmic enzymes or periplasmic bodies with each other.One or more independent bodies may be seen in the periplasmic space between outer and inner membranes of Gram-negative bacteria, which we called periplasmic bodies. The periplasmic bodies have been found in seven species of bacteria at least, including the Pseudomonas aeroginosa. Shigella flexneri, Echerichia coli. Yersinia pestis, Campylobacter jejuni, Proteus mirabilis, Clostridium tetani. Vibrio cholerae and Brucella canis.

Dual stain kit for the microscopic gram classification of ocular infection bacteria

1993 ◽  
Vol 51 ◽  
pp. 248-249
Author(s):  
Jacob S. Hanker ◽  
Dale N. Holdren ◽  
Kenneth L. Cohen ◽  
Beverly L. Giammara
Keyword(s):  
Contact Lenses ◽  
Ocular Infection ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Gram Staining ◽  
Ocular Infections ◽  
Different Types ◽  
Culture Positive ◽  
Increased Susceptibility

Keratitis and conjunctivitis (infections of the cornea or conjunctiva) are ocular infections caused by various bacteria, fungi, viruses or parasites; bacteria, however, are usually prominent. Systemic conditions such as alcoholism, diabetes, debilitating disease, AIDS and immunosuppressive therapy can lead to increased susceptibility but trauma and contact lens use are very important factors. Gram-negative bacteria are most frequently cultured in these situations and Pseudomonas aeruginosa is most usually isolated from culture-positive ulcers of patients using contact lenses. Smears for staining can be obtained with a special swab or spatula and Gram staining frequently guides choice of a therapeutic rinse prior to the report of the culture results upon which specific antibiotic therapy is based. In some cases staining of the direct smear may be diagnostic in situations where the culture will not grow. In these cases different types of stains occasionally assist in guiding therapy.

Neutrophil pseudoplatelets in subgingival plaque and crevicular fluid samples from periodontal diseased sites

1989 ◽  
Vol 47 ◽  
pp. 862-863 ◽  
Author(s):  
J Hanker ◽  
E.J. Burkes ◽  
G. Greco ◽  
R. Scruggs ◽  
B. Giammara
Keyword(s):  
Electron Microscopy ◽  
Bone Marrow ◽  
Peripheral Blood ◽  
Gingival Crevicular Fluid ◽  
Light And Electron Microscopy ◽  
Subgingival Plaque ◽  
Staining Reaction ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Crevicular Fluid

The mature neutrophil with a segmented nucleus (usually having 3 or 4 lobes) is generally considered to be the end-stage cell of the neutrophil series. It is usually found as such in the bone marrow and peripheral blood where it normally is the most abundant leukocyte. Neutrophils, however, must frequently leave the peripheral blood and migrate into areas of infection to combat microorganisms. It is in such areas that neutrophils were first observed to fragment to form platelet-size particles some of which have a nuclear lobe. These neutrophil pseudoplatelets (NPP) can readily be distinguished from true platelets because they stain for neutrophil myeloperoxidase. True platelets are not positive in this staining reaction because their peroxidase Is inhibited by glutaraldehyde. Neutrophil pseudoplatelets, as well as neutrophils budding to form NPP, could frequently be observed in peripheral blood or bone marrow samples of leukemia patients. They are much more prominent, however, in smears of inflammatory exudates that contain gram-negative bacteria and in gingival crevicular fluid samples from periodontal disease sites. In some of these samples macrophages ingesting, or which contained, pseudoplatelets could be observed. The myeloperoxidase in the ingested pseudoplatelets was frequently active. Despite these earlier observations we did not expect to find many NPP in subgingival plaque smears from diseased sites. They were first seen by light microscopy (Figs. 1, 3-5) in smears on coverslips stained with the PATS reaction, a variation of the PAS reaction which deposits silver for light and electron microscopy. After drying replicate PATS-stained coverslips with hexamethyldisilazane, they were sputter coated with gold and then examined by the SEI and BEI modes of scanning electron microscopy (Fig. 2). Unstained replicate coverslips were fixed, and stained for the demonstration of myeloperoxidase in budding neutrophils and NPP. Neutrophils, activated macrophages and spirochetes as well as other gram-negative bacteria were also prominent in the PATS stained samples. In replicate subgingival plaque smears stained with our procedure for granulocyte peroxidases only neutrophils, budding neutrophils or NPP were readily observed (Fig. 6).

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