Search results for " Listeria"
showing 8 items of 18 documents
Una soluzione oleosa capace di prevenire la formazione di biofilm di Listeria monocytogenes
2014
La Listeria monocytogenes è un batterio patogeno che può causare gastroenteriti lievi o gravi infezioni del sangue e del sistema nervoso, con tassi di mortalità tra il 20% e il 67%. È trasmesso all'uomo prevalentemente attraverso il cibo e può colpire le donne in gravidanza causando l’aborto. La malattia causata da questo batterio ha il nome di listeriosi e appartiene al gruppo di patologie definibili come “tossinfezioni alimentari”. Diversi focolai di listeriosi, associati con i prodotti alimentari “pronti da mangiare”, sono stati attribuiti a una combinazione di contaminazione di L. monocytogenes, durante la lavorazione e la successiva crescita nei prodotti durante lo stoccaggio. Oltre a …
Chemical Composition and Antibacterial Potential of Artemisia arborescens L. Essential Oil
2011
This study was undertaken to characterize the essential oil (EO) of Artemisia arborescens growing wild in Sicily. EO, extracted by steam distillation, was examined for its chemical composition and for its capability to inhibit some food-borne pathogen bacteria. A total of 43 compounds (13 monoterpene hydrocarbons, 14 oxygenated monoterpenes, 10 sesquiterpene hydrocarbons, three oxygenated sesquiterpenes and less amount of other three compounds), which account 93.73% of the total oil, were identified by gas chromatography and gas chromatography-mass spectrometry. Oxygenated monoterpenes (57.32%) constituted the main fraction, with β-thujone as the main compound (45.04%), followed by the sesq…
Control of biofilm formation by poly-ethylene-co-vinyl acetate films incorporating nisin.
2010
The aim of this study was to evaluate the effect of poly-ethylene-co-vinyl acetate (EVA) films incorporating different concentrations (0.1%, 0.5% and 1%) of nisin on the biofilm-forming ability of Listeria monocytogenes ATCC 7644, Staphylococcus aureus 815 and Staphylococ-cus epidermidis ATCC 35984. Nisin was incorporated into two grades of EVA (EVA14 and EVA28) in the melt during a common film-blowing operation. The efficacy of EVA/nisin films was evaluated by biofilm biomass measurements and Live/Dead staining in combination with fluorescence microscopy. In order to evaluate whether the nisin incorporation could modify the film surface properties, contact angle measurements and scanning e…
A stochastic interspecific competition model to predict the behaviour of Listeria monocytogenes in the fermentation process of a traditional Sicilian…
2008
The present paper discusses the use of modified Lotka-Volterra equations in order to stochastically simulate the behaviour of Listeria monocytogenes and Lactic Acid Bacteria (LAB) during the fermentation period (168 h) of a typical Sicilian salami. For this purpose, the differential equation system is set considering T, pH and aw as stochastic variables. Each of them is governed by dynamics that involve a deterministic linear decrease as a function of the time t and an "additive noise" term which instantaneously mimics the fluctuations of T, pH and aw. The choice of a suitable parameter accounting for the interaction of LAB on L. monocytogenes as well as the introduction of appropriate nois…
Differential expression of the agr locus of Listeria monocytogenes EGD-e
2007
International audience
Indigenous Listeria spp. in biowastes and during composting
2007
International audience
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.
Ruolo del rumore ambientale in sistemi complessi di natura biologica
2010
La Fisica dei Sistemi Complessi ha recentemente assunto un ruolo sempre più importante nella descrizione dei sistemi biologici a causa delle interazioni, sia deterministiche sia rumorose o “randomiche”, di tali sistemi con l’ambiente. La presenza del rumore diviene particolarmente rilevante nella trattazione dei sistemi biologici in ambito medico. In questo lavoro vengono presentati due diversi sistemi: i) un modello di dinamica di popolazioni che descrive lo sviluppo delle cellule tumorali responsabili della Leucemia Mieloide Cronica (CML); ii) un modello stocastico che riproduce la crescita di batteri in alimenti di origine animale. Nel primo sistema viene utilizzato un approccio Monte Ca…