Pseudomonas aeruginosa related to Nosocomial and Animal infections. New approaches in diagnosis and therapy

Pseudomonas aeruginosa is a small bacillus gram negative, aerobic, asporogenous, monoflagellate, non-fermenting. P. aeruginosa infections often have a very severe course and are difficult to treat because of its ability to form biofilms characterized by a thick capsule coated with alginate (an exopolysaccharide consisting of D-mannuronic acid and glucuronic acid monomers). Alginate represent the main component of the extracellular matrix of P. aeruginosa biofilm; as a consequence, the alginate lysis facilitates the spread of antimicrobial substances. In fact, this extracellular matrix makes these micro-organisms resistant to antimicrobial agents and leads to the emergence of multidrug resistant clinical isolates (MDR) during therapy. Mutations in the mucA gene encode a protein involved in the production of this exopolysaccharide. In fact, in vitro inactivation of mucA in Pseudomonas aeruginosa PAO1 (non-mucoid) produces Alg+ strains; this seems to indicate, therefore, that mucA acts as a negative regulator of the production of alginate because it can bind and sequester the factor σ22, through the N-terminal cytoplasmic domain. The risk of P. aeruginosa infection may be related to several factors such as: (i) inappropriate therapies or prophylaxis measures, (ii) failure in the environmental monitoring systems (iii) inadequate laboratory protocols for detecting MDR strains. For example, the inappropriate use of peroxides as disinfectants could be increase the mutation rate in mucA gene. In this context, the P. aeruginosa biofilm studies allow to characterize new antimicrobials and to ascertain what are the useful ranges of the disinfectant that do not induce the mucoid phenotype more virulent and more resistant respectively to the not mucoid phenotype. Mutations present in the promoter of the gene or along the amino terminal part of the protein modulate an alginate hyper-expression giving the biofilm a barrier almost impermeable to the antimicrobials, this aspect must be considered during the use of oxidizing microbicides such as hydrogen peroxides, in able to determine mutations in the mucA gene. This work aims to study P. aeruginosa infections and its environmental contaminations as a global health problem. In fact, this multi-task pathogen can contaminate different areas in human, veterinary and agricultural fields. For this reason, a comprehensive work must be performed by different strategies in these points: 1 Pathogen detection: in this work, we describe a fast-molecular approach to detect the initial pathogen biofilm samples contaminated with Pseudomonas spp. (P. aeruginosa, P. fluorescens and P. putida). This procedure is based on the particular bi-functional FRET oligonucleotide probes named DUAL-FRET. 2 mucA / alginate profile: in P. aeruginosa, mucA genotype resulted essential to reveal high drug-resistant strains due to alginate hyperproduction in the biofilm. 3 Evaluation of potential new antimicrobials: a critical point in anti - P. aeruginosa prophylaxis is represented by the absence of highly performant disinfectant. 4 New cultural systems: design/use of bioreactors able to reproduce, in standard controlled conditions, the initial parameters in the primary contamination area, for example the cold storage implants in the food production 5 Future strategies: following the recent new molecular procedures obtained in biological field could be possible to design new clinical/laboratory strategies against P. aeruginosa, for example the study of miRNAs

Texture evolution of "Amaretti" cookies during storage

The results of a study on texture evolution during 35 days of storage of ldquoamarettirdquo, a typical Italian cookie, packaged in two different ways are reported. Amaretti cookies were wrapped in polyvinylchloride (PVC) film or aluminium foil (ALL), to simulate two different permeability conditions and stored at controlled temperature and humidity. Evolution of texture (such as hardness) and aw were tested instrumentally by a texture analyser and a hygrometer, respectively. Texture was assessed by a cut and puncturing test. Indices for hardening were the area under the curve (N mm) and gradient (N/mm) for the puncturing test and maximum force (N) for the cut test. Both textural tests showed significantly higher hardening of PVC cookies, compared to the ALL cookies. The latter retained good sensorial properties at the end of the storage period, although their internal structure changed from soft and moist to mealy, while the PVC cookies were no longer edible only 10 days after baking. aw values decreased and increased in PVC and ALL lots, respectively. The results suggest that hardening may be explained by water loss in PVC and moisture redistribution in ALL

Cigarette Smoking and Dyspnea Perception

Cigarette smoking has been implicated as an important risk factor for the development of respiratory symptoms in adults. The relationship of dyspnea with cigarette smoking has been examined in smokers and ex-smokers and the beneficial effects of smoking cessation have been demonstrated. Recent studies reported that in subjects who smoke cigarettes the risk of developing respiratory symptoms is higher in a dose-dependent way. Environmental tobacco smoke heavily influences the incidence of respiratory symptoms in both adults and in children. Up to the present time, the mechanisms whereby cigarette smoking causes dyspnea perception remain to be defined. Abnormalities in sensory nerves might diminish the perception of bronchoconstriction in smokers. In this regard, it has been postulated that prolonged exposure to cigarette smoke may lead to chronic depletion of sensory nerve neurotransmitters. Eosinophil airway inflammation has been proposed as a determinant of breathlessness via mechanisms affecting either the mechanical pathways that control breathlessness or the afferent nerves involved in perception of dyspnea. An increased number of eosinophils in some smokers implies the possibility that smoking may trigger immunological or other reactions associated with eosinophilia. In conclusion, cigarette smoking is by far one of the greatest risk factors for most respiratory symptoms, including dyspnea. Smoking is associated with the development of symptoms in a dose-dependent way and eosinophilia and airway hyperresponsiveness (AHR) increase the risk of developing dyspnea

Effects of additives and ingredient sizing on the shelf-life of "Amaretti" cookies

Cookies are characterised by moisture and water activity (aw) higher than 7% and 0.5, respectively. Cookies have the capacity of bending after baking, when they are fresh, unlike biscuits that break when bent. Hardening is the main cause of quality deterioration of cookies, which change from soft and pliable to firm and crumbly within a few days or even hours after baking. Little research has been done on cookies. "Amaretti" are typical Italian cookies, found in several regions of Italy. Freshly baked "Amaretti" are soft and delicious but undergo severe hardening after seven to ten days, thus limiting the shelf-life, so Amaretti can be marketed only locally. In the present work several attempts have been made in order to extend the shelf-life of Sardinian "Amaretti". In particular, changes to the formulation and to the almond particle size were made. The traditional formulation was, in fact, modified by adding rice starch (thickening agent) or mono-diglyceride of fatty acids (emulsifier). Almonds were grinded to a particle size lower or higher than 1 mm. Amaretti baked with the traditional recipe were used as control. After baking and cooling cookies were wrapped with an aluminium foil and stored at controlled temperature and humidity. Evolution of texture (as hardness) and aw during storage were followed instrumentally by a texture analyser and a hygrometer, respectively

A metabolomic approach to animal vitreous humor topographical composition: A pilot study

The purpose of this study was to evaluate the feasibility of a 1H-NMR-based metabolomic approach to explore the metabolomic signature of different topographical areas of vitreous humor (VH) in an animal model. Five ocular globes were enucleated from five goats and immediately frozen at 280uC. Once frozen, three of them were sectioned, and four samples corresponding to four different VH areas were collected: the cortical, core, and basal, which was further divided into a superior and an inferior fraction. An additional two samples were collected that were representative of the whole vitreous body. 1H-NMR spectra were acquired for twenty-three goat vitreous samples with the aim of characterizing the metabolomic signature of this biofluid and identifying whether any site-specific patterns were present. Multivariate statistical analysis (MVA) of the spectral data were carried out, including Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), and Partial Least Squares Discriminant Analysis (PLS-DA). A unique metabolomic signature belonging to each area was observed. The cortical area was characterized by lactate, glutamine, choline, and its derivatives, N-acetyl groups, creatine, and glycerol; the core area was characterized by glucose, acetate, and scyllo-inositol; and the basal area was characterized by branched-chain amino acids (BCAA), betaine, alanine, ascorbate, lysine, and myo-inositol. We propose a speculative approach on the topographic role of these molecules that are mainly responsible for metabolic differences among the as-identified areas. 1H-NMR-based metabolomic analysis has shown to be an important tool for investigating the VH. In particular, this approach was able to assess in the samples here analyzed the presence of different functional areas on the basis of a different metabolite distribution.The purpose of this study was to evaluate the feasibility of a 1H-NMR-based metabolomic approach to explore the metabolomic signature of different topographical areas of vitreous humor (VH) in an animal model. Five ocular globes were enucleated from five goats and immediately frozen at -80°C. Once frozen, three of them were sectioned, and four samples corresponding to four different VH areas were collected: the cortical, core, and basal, which was further divided into a superior and an inferior fraction. An additional two samples were collected that were representative of the whole vitreous body. 1H-NMR spectra were acquired for twenty-three goat vitreous samples with the aim of characterizing the metabolomic signature of this biofluid and identifying whether any site-specific patterns were present. Multivariate statistical analysis (MVA) of the spectral data were carried out, including Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), and Partial Least Squares Discriminant Analysis (PLS-DA). A unique metabolomic signature belonging to each area was observed. The cortical area was characterized by lactate, glutamine, choline, and its derivatives, N-acetyl groups, creatine, and glycerol; the core area was characterized by glucose, acetate, and scyllo-inositol; and the basal area was characterized by branched-chain amino acids (BCAA), betaine, alanine, ascorbate, lysine, and myo-inositol. We propose a speculative approach on the topographic role of these molecules that are mainly responsible for metabolic differences among the as-identified areas. 1H-NMR-based metabolomic analysis has shown to be an important tool for investigating the VH. In particular, this approach was able to assess in the samples here analyzed the presence of different functional areas on the basis of a different metabolite distribution. © 2014 Locci et al