Search results for "ANTIMICROBIAL PEPTIDES"
showing 10 items of 76 documents
FRAGMENTS OF BETA-THYMOSIN FROM THE SEA-URCHIN PARACENTROTUS LIVIDUS AS NOVEL ANTIMICROBIAL PEPTIDES AGAINST STAPHYLOCOCCAL BIOFILMS
2012
With the aim to face the threat of pathogen biofilms intrinsically resistant to conventional antibiotics, we focused on coelomocytes, the immune mediators in echinoderms, as source of novel antimicrobial peptides (AMPs). The proteic fraction <5kDa from coelomocytes cytosol of the sea-urchin Paracentrotus lividus (5-CC) was tested against a group of Gram positive and Gram negative pathogen reference strains. The 5-CC of P. lividus resulted active against all tested strains at concentrations ranging from 15.8 to 253.7 mg/mL. The ability to prevent staphylococcal biofilm formation was evaluated against the biofilm of clinical strain S.epidermidis 1457 using live/dead staining in combination wi…
Identification of antimicrobial peptides in the gonad of European sea bass males and females
2015
In vertebrates, the gonad is considered an immunologically privileged site as it triggers lower immune responses aiming to avoid germ cell damage. In fish,several studies reported that leucocytes show conditioned immune response and modulate some reproductive functions, allowing the pathogen to establish chronic and latent infections into reproductive organs. In mammals, antimicrobial peptides (AMPs) have recently been recognised as important effectors in male reproductive tract immunity. In fish, AMPs are increasingly recognized as a critical first line of defence against many pathogens as bacteria, fungi, virus, protozoa and even tumour cells. We have recently determined that the European…
Role of the virulence plasmid pR99 and the metalloprotease Vvp in resistance of Vibrio vulnificus serovar E to eel innate immunity
2007
Vibrio vulnificus biotype 2 serovar E (VSE) is a bacterial pathogen that produces a haemorrhagic septicaemia called vibriosis in eels. Its ability to grow in blood is conferred by a recently described virulence plasmid [Lee CT, Amaro C, Wu KM, Valiente E, Chang YF, Tsai SF, et al. A common virulence plasmid in biotype 2 Vibrio vulnificus and its dissemination aided by a conjugal plasmid. Journal of Bacteriology, submitted for publication.]. In this study, we analyzed the role of this plasmid together with the role played by the metalloprotease (Vvp) in the interaction between bacteria and eel innate immunity. To this end, we compared and statistically analyzed the differences in resistance …
Marine organisms as source of bioactive molecules applied in restoration projects
2015
Abstract In recent decades research in the conservation and restoration field has provided sustainable alternatives to traditional procedures for cleaning or controlling the microbial colonization of works of art. In the present study, for the first time novel bioactive molecules extracted from marine invertebrate organisms (Anthozoa) were tested instead of chemical compounds for removing protein layers or as a biocide for controlling fungal or bacterial colonization. In particular, Bioactive Molecules with Protease activity (BMP), acting in a temperature range of 4- 30°C, were tested for the hydrolysis of protein layers on laboratory specimens. The cleaning protocol provides a selective pr…
Of Cockroaches and Symbionts: Recent Advances in the Characterization of the Relationship between Blattella germanica and Its Dual Symbiotic System
2022
This article belongs to the Collection Feature Review Papers for Life.
Comparison of the activity of antifungal hexapeptides and the fungicides thiabendazole and imazalil against postharvest fungal pathogens
2003
8 pages, 2 figures, 3 tables.-- PMID: 14623382 [PubMed].-- Printed version published Dec 31, 2003.
Epithelial NEMO links innate immunity to chronic intestinal inflammation
2007
Deregulation of intestinal immune responses seems to have a principal function in the pathogenesis of inflammatory bowel disease(1-4). The gut epithelium is critically involved in the maintenance of intestinal immune homeostasis-acting as a physical barrier separating luminal bacteria and immune cells, and also expressing antimicrobial peptides(3,5,6). However, the molecular mechanisms that control this function of gut epithelial cells are poorly understood. Here we show that the transcription factor NF kappa B, a master regulator of pro-inflammatory responses(7,8), functions in gut epithelial cells to control epithelial integrity and the interaction between the mucosal immune system and gu…
Toxic Proteins and Peptides
1994
Many animals produce poisonous substances which, even at a relatively low dose, are deleterious or lethal to other organisms, including man. They may serve on the one hand to disable or kill prey, or on the other hand as a protection or defence against predators. These substances are mostly produced by special glands, and both poison reservoirs and specialized structures for delivering the secretion, e.g. stings or modified mouthparts or fangs, are usually also present. In accordance with the aims of this book, we will deal with the comparative biochemistry of the animal toxins as natural products with special structures and functions; a discussion of the mechanisms of their pharmacological…
Microbiome symbionts and diet diversity incur costs on the immune system of insect larvae
2017
Communities of symbiotic microorganisms that colonize the gastrointestinal tract play an important role in food digestion and protection against opportunistic microbes. Diet diversity increases the number of symbionts in the intestines, a benefit that is considered to impose no cost for the host organism. However, less is known about the possible immunological investments that hosts have to make in order to control the infections caused by symbiont populations that increase due to diet diversity. By using taxonomical composition analysis of the 16S rRNA V3 region, we show that Enterococci are the dominating group of bacteria in the midgut of the larvae of the greater wax moth (Galleria mell…
Echinoderm Antimicrobial Peptides
2016
Abstract Antimicrobial peptides (AMPs) are widely expressed in organisms and have been linked to innate and acquired immunity in vertebrates. These compounds are constitutively expressed from different cellular types to interact directly with infectious agents and/or modulate immunoreactions. In invertebrates, including echinoderms, which lack a vertebrate-type adaptive immune system, AMPs represent the major humoral defense system against infection, showing a diverse spectrum of action mechanisms, most of them related to plasma membrane disturbance and lethal alteration of microbial integrity. Here, we summarize the knowledge of AMPs in echinoderms as Strongylocins identified in the sea ur…