Search results for "antimicrobial"
showing 10 items of 707 documents
Differential involvement of mussel hemocyte sub-populations in the clearance of bacteria.
2008
Abstract Mussels are filter-feeders living in a bacteria-rich environment. We have previously found that numerous bacterial species are naturally present within the cell-free hemolymph, including several of the Vibrio genus, whereas the intra-cellular content of hemocytes was sterile. When bacteria were injected into the circulation of the mussel, the number of living intra-hemocyte bacteria dramatically increased in less than an hour, suggesting intense phagocytosis, then gradually decreased, with no viable bacteria remaining 12 h post-injection for Micrococcus lysodeikticus, 24 h for Vibrio splendidus and more than 48 h for V ibrio anguillarum. The total hemocyte count (THC) was dramatica…
Specific expression of antimicrobial peptide and HSP70 genes in response to heat-shock and several bacterial challenges in mussels
2007
Abstract Defensin, mytilin and myticin are antimicrobial peptides (AMP) involved in mussel innate immunity. Their in vitro antibacterial activity is different according to the targeted bacterial species. To determine if this specificity is correlated to different regulations of gene expressions, adult mussels were challenged in vivo with either Vibrio splendidus LGP32, Vibrio anguillarum , Micrococcus lysodeikticus or by heat shock. RNAs were isolated from circulating hemocytes and AMP mRNAs were quantified by Q-PCR using 28S rRNA as housekeeping gene. In addition, HSP70 gene expression was also quantified as representing non-specific response to stress. In naive mussels, the three AMP mRNA…
Tropical traditional fermented food, a field full of promise. Examples from the Tropical Bioresources and Biotechnology programme and other related F…
2013
International audience; In tropical countries, traditional fermented foods are usually home‐made products obtained through spontaneous fermentation or backslopping. They are now facing an evolution aiming at responding to quality, safety and mass production issues. This requires acquisition of knowledge on raw materials, microbial ecosystems and fermentation processes. Vietnam is a laboratory for such studies as traditional fermented foods play an important role in the diet of Vietnamese and as these foods are very diverse. Among the most popular are nem chua (sausage reminding Thai Nham), dua muoi (cabbage reminding Kimchi), tom chua (shrimps) and the well‐known nuoc mam. The challenge for…
Sortase A: An ideal target for anti-virulence drug development
2014
Sortase A is a membrane enzyme responsible for the anchoring of surface-exposed proteins to the cell wall envelope of Gram-positive bacteria. As a well-studied member of the sortase subfamily catalysing the cell wall anchoring of important virulence factors to the surface of staphylococci, enterococci and streptococci, sortase A plays a critical role in Gram-positive bacterial pathogenesis. It is thus considered a promising target for the development of new anti-infective drugs that aim to interfere with important Gram-positive virulence mechanisms, such as adhesion to host tissues, evasion of host defences, and bio fi lm formation. The additional properties of sortase A as an enzyme that i…
Ultrasound as a Promising Tool for the Green Extraction of Specialized Metabolites from Some Culinary Spices
2021
Spices are a popular food of plant origin, rich in various phytochemicals and recognized for their numerous properties. The aim of the study was to evaluate the antioxidant and antimicrobial activity, as well as the content of specialized metabolites, of aqueous extracts of three spice species––garlic (Allium sativum L.), ginger (Zingiber officinalle L.) and turmeric (Curcuma longa L.)––prepared by green extraction methods. Ultrasound treatment increased the chromaticity parameter b value of turmeric and ginger extracts, thus indicating a higher yellow color predominantly due to curcuminoids characteristic of these species. Ultrasound-assisted extraction significantly increased the content …
Salmo salar fish waste oil: Fatty acids composition and antibacterial activity
2020
Background and aims Fish by-products are generally used to produce fishmeal or fertilizers, with fish oil as a by-product. Despite their importance, fish wastes are still poorly explored and characterized and more studies are needed to reveal their potentiality. The goal of the present study was to qualitatively characterize and investigate the antimicrobial effects of the fish oil extracted from Salmo salar waste samples and to evaluate the potential use of these compounds for treating pathogen infections. Methods Salmo salar waste samples were divided in two groups: heads and soft tissues. Fatty acids composition, and in particular the content in saturated (SAFAs), mono-unsaturated (MUFA…
Synergistic and Antagonistic Effects of Combined Subzero Temperature and High Pressure on Inactivation of Escherichia coli
2006
ABSTRACT The combined effects of subzero temperature and high pressure on the inactivation of Escherichia coli K12TG1 were investigated. Cells of this bacterial strain were exposed to high pressure (50 to 450 MPa, 10-min holding time) at two temperatures (−20°C without freezing and 25°C) and three water activity levels (a w ) (0.850, 0.992, and ca. 1.000) achieved with the addition of glycerol. There was a synergistic interaction between subzero temperature and high pressure in their effects on microbial inactivation. Indeed, to achieve the same inactivation rate, the pressures required at −20°C (in the liquid state) were more than 100 MPa less than those required at 25°C, at pressures in t…
A Novel Na(I) Coordination Complex with s-Triazine Pincer Ligand: Synthesis, X-ray Structure, Hirshfeld Analysis, and Antimicrobial Activity
2023
The pincer ligand 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (bpmt) was used to synthesize the novel [Na(bpmt)2][AuCl4] complex through the self-assembly method. In this complex, the Na(I) ion is hexa-coordinated with two tridentate N-pincer ligands (bpmt). The two bpmt ligand units are meridionally coordinated to Na(I) via one short Na-N(s-triazine) and two slightly longer Na-N(pyrazole) bonds, resulting in a distorted octahedral geometry around the Na(I) ion. In the coordinated bpmt ligand, the s-triazine core is not found to be coplanar with the two pyrazole moieties. Additionally, the two bpmt units are strongly twisted from one another by 64.94°. Based on Hirshf…
Synthesis, X-ray Structure, Antimicrobial and Anticancer Activity of a Novel [Ag(ethyl-3-quinolate)2(citrate)] Complex
2022
A novel Ag(I) citrate complex with ethyl-3-quinolate (Et3qu) was synthesized. Its structure was confirmed using X-ray single crystal to be [Ag(Et3qu)2(citrate)]. It crystallized in the Triclinic crystal system and P-1 space group with unit cell parameters of a = 8.6475(2) Å, b = 11.4426(3) Å, c = 15.2256(3) Å, α = 73.636(2)°, β = 79.692(2)° and γ = 86.832(2)°, while the unit cell volume was 1422.19(6) Å3. In the unit cell, there are two [Ag(Et3qu)2(citrate)] molecules and one unit as the asymmetric formula. The molecular structure comprised one Ag(I) coordinated with two Et3qu molecules via two almost equidistant Ag-N bonds and one citrate ion acting as a mono-negative monodentate ligand vi…
Antimicrobial Activity of Resveratrol Analogues
2014
Stilbenes, especially resveratrol and its derivatives, have become famous for their positive effects on a wide range of medical disorders, as indicated by a huge number of published studies. A less investigated area of research is their antimicrobial properties. A series of 13 trans-resveratrol analogues was synthesized via Wittig or Heck reactions, and their antimicrobial activity assessed on two different grapevine pathogens responsible for severe diseases in the vineyard. The entire series, together with resveratrol, was first evaluated on the zoospore mobility and sporulation level of Plasmopara viticola (the oomycete responsible for downy mildew). Stilbenes displayed a spectrum of acti…