Search results for "Bacterial"

Immunization of rainbow trout, Oncorhynchus mykiss (Walbaum), with a low molecular mass fraction isolated from Flavobacterium psychrophilum.

2008

Flavobacterium psychrophilum, the causative agent of rainbow trout fry syndrome has become a widespread fish pathogen in freshwater aquaculture worldwide. In this study, a low molecular mass fraction (P25-33), with an approximate weight of 25-33 kDa, was identified among F. psychrophilum strains in an immunoblotting analysis with anti-F. psychrophilum sera. The immunogenic efficacy of the isolated and extracted P25-33 was investigated in two intraperitoneal immunization trials with rainbow trout, Oncorhynchus mykiss (Walbaum). The first trial included immunizations using P25-33 with Freund's complete adjuvant (FCA) and the second trial included immunizations using P25-33, formalin-inactivat…

Essential oils as multi-target compounds for novel food safety strategies

This research work has been developed in the context of the potencial applications of essential oils as multi-target compounds for novel food safety strategies, such as active packaging technologies. Essential oils are aromatic oils derived from plants and usually extracted by hydrodistillation when intended to be used in food. There is an increasing interest in the antimicrobial properties of essential oils due to the possibility of using them to replace ‘synthetic’ preservatives in food or, in general, to reduce viable numbers of pathogens along the food chain.

Photocatalytic activity of N-doped TiO2-based materials embedded with gold NPs for applications in antibacterial photodynamic therapy (aPDT)

Antibacterial photodynamic therapy (aPDT) is a potential treatment for antibiotic-resistant bacterial infections. It is based on the photosensitization of bacterial cells with exogenous agents that, when exposed to light, produce reactive oxygen species (ROS), such as OH-, O2-, H2O2. ROS can induce complex oxidative-reductive chains of reactions, resulting in damage of cellular components in target tissues1. Photocatalysts, like inorganic semiconductor oxides, represent an interesting class of materials to design new strategies for aPTD. As exposed to light of proper wavelengths, photocatalysts induce the formation of electron-hole pairs capable of producing a cascade of reactions suitable …

Water-stable cellulose fiber foam with antimicrobial properties for bio based low-density materials

2018

New bio-based packaging materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Waterstable cellulose fiber foams have been produced in a simple one-batch foam-forming process with drying under ambient conditions. The cellulose fiber foams have a low density (33–66 kg/m3) and can inhibit microbial growth; two highly valuable features for insulating packaging materials, especially in combination with stability in water. Cationic chitosan and/or polyvinylamine have been added during the foamforming process to give the foams water-stability and antimicrobial properties. The structural and mechanical properties of the cellulose fiber foa…

Simulating multilevel dynamics of antimicrobial resistance in a membrane computing model

2019

Membrane computing is a bio-inspired computing paradigm whose devices are the so-called membrane systems or P systems. The P system designed in this work reproduces complex biological landscapes in the computer world. It uses nested “membrane-surrounded entities” able to divide, propagate, and die; to be transferred into other membranes; to exchange informative material according to flexible rules; and to mutate and be selected by external agents. This allows the exploration of hierarchical interactive dynamics resulting from the probabilistic interaction of genes (phenotypes), clones, species, hosts, environments, and antibiotic challenges. Our model facilitates analysis of several aspects…

Prevenzione dell’occlusione delle protesi biliari mediante somministrazione di levofloxacina e acido ursodesossicolico.

2004

One of the main advances in biliopancreatic endoscopic therapy has been the ability to palliate patients with biliary obstruction by placement of a stent during ERCP, but this is often complicated by clogging of the stent with subsequent jaundice and/or cholangitis. Stent clogging may be caused by microbiological adhesion and biliary stasis. Therefore, the use of antibiotics and choleretic agents such as levofloxacin and ursodeoxycholic acid has been investigated to see whether they prolong stent patency. Ninety patients with strictures of the biliary tract and untreatable macrolithiasis with endoscopically inserted stents were randomized into two groups: 49 subjects in group 1 (levofloxaci…

Composition and antimicrobial activity of the essential oil of Achillea falcata L. (Asteraceae).

2005

The composition of the essential oil from aerial parts of Achillea falcata L. (Asteraceae) growing wild in Lebanon was analysed by GC and GC–MS; 58 compounds, representing 94.4% of the oil, were identified. Isomers of the cyclobutane ethanol, 1-methyl-2-(1-methylethenyl), grandisol (21.4%) and fragranol (16.8%) were the main components of the oil. Also abundant were artemisia ketone (5.2%), terpinen-4-ol (4.5%) and 1,8-cineole (4.0%). The essential oil shows inhibitory activity mainly against Gram-positive bacteria.

A synthetic derivative of antimicrobial peptide holothuroidin 2 from mediterranean sea cucumber (Holothuria tubulosa) in the control of Listeria mono…

2019

Due to the limited number of available antibiotics, antimicrobial peptides (AMPs) are considered antimicrobial candidates to fight difficult-to-treat infections such as those associated with biofilms. Marine environments are precious sources of AMPs, as shown by the recent discovery of antibiofilm properties of Holothuroidin 2 (H2), an AMP produced by the Mediterranean sea cucumber Holothuria tubulosa. In this study, we considered the properties of a new H2 derivative, named H2d, and we tested it against seven strains of the dangerous foodborne pathogen Listeria monocytogenes. This peptide was more active than H2 in inhibiting the growth of planktonic L. monocytogenes and was able to interf…

PVC silver zeolite composites with antimicrobial properties

2011

Poly(vinyl chloride) (PVC) composites containing increasing amounts (2-20%, w/w) of silver zeolite (SZ) were prepared by melt mixing and characterized by thermal, mechanical and rheological analyses. The addition of large amount of SZ did not influence the processability and the formability of the composites, if compared to neat plasticized PVC. The antibacterial activity of PVC SZ composites was tested on Escherichia coli and Staphylococcus epidermidis and resulted promising both in culture broth and on agar plate and also in sterile urine seeded with these strains, for simulation purposes. In sterile urine, composites induced a significant reduction (4-6 log units) of viability of both st…

Supramolecular Structure and Antimicrobial Activity of Ni(II) Complexes with s-Triazine/Hydrazine Type Ligand

2023

The two complexes, [Ni(DPPT)2](NO3)2*1.5H2O (1) and [Ni(DPPT)(NO3)Cl].EtOH (2), were synthesized using the self-assembly of (E)-2,4-di(piperidin-1-yl)-6-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)-1,3,5-triazine (DPPT) with Ni(NO3)2*6H2O in the absence and presence of NiCl2*6H2O, respectively. In both cases, the neutral tridentate DPPT ligand is found coordinated to the Ni(II) via three N-atoms from the hydrazone, pyridine and s-triazine rings. Hence, the homoleptic complex 1 has a NiN6 hexa-coordination environment while two NO3− are counter anions in addition to one-and-a-half crystallized hydration water molecules are found acting as an outer sphere. The heteroleptic complex 2 has a NiN3O…