RUOLO DEGLI INTEGRONI NELLA TRASMISSIONE DI ANTIBIOTICO- RESISTENZE IN ACINETOBACTER

2001/2002XV Ciclo1974Versione digitalizzata della tesi di dottorato cartacea

Collaborative Interlaboratory Studies for the Validation of ELISA Methods for the Detection of Allergenic Fining Agents Used in Wine According to the Criteria of OIV Resolution 427–2010 Modified by OIV–Comex 502–2012

The clarification or fining of wine removes undesired substances (mainly proteins, phenols, and tannins), which would roil the wine and cause bitterness and astringency. A common fining agent, egg white, can be directly added to wine through the inlet of a circulating pump, but more typically egg white comes as commercial preparation in powdered form (commercially named egg albumin). Skimmed milk or more frequently purified caseinates are used to remove bitterness and hardness of white wine and sherry. Both egg white and caseinates are fining agents with optimal enological properties, but their residues could represent a risk for subjects suffering from food allergy. The rules for allergen labeling were detailed in Directives 2003/89/EC, and Directive 2005/26/EC established a list of food ingredients provisionally excluded from labeling, that included wine fining agents. Extended till June 2012, wine labeling exemption can be now maintained only if (1) egg and milk derivatives are not used and cross-contamination is under control; and (2) wine clarified with such products is negative for the presence of residues using techniques with detection and quantification limits of 0.25 and 0.5 ppm, respectively. Analytical requirements were defined in the OIV resolution 427–2010 (OIV 2010) modified by OIV/COMEX 502–2012 (OIV 2012). On the basis of a previous experience, an interlaboratory collaborative trial was organized to validate a commercial ELISA kit designed to measure allergenic residues in red wine fined with egg white proteins. In the meantime, the performance of the commercial caseinate ELISA kit for white wine was rechecked according to the new limit of detection and limit of quantification values, recommended by OIV in 2012. The collaborative interlaboratory studies showed that both ELISA kits had good reproducibility, repeatability, and robustness in detecting residues of allergenic fining agents in wine, in good agreement with the requirements of the OIV resolution 427–2010 modified by OIV/COMEX 502–2012

Molecular Characterization of Integrons in Epidemiologically Unrelated Clinical Isolates of Acinetobacter baumannii from Italian Hospitals Reveals a Limited Diversity of Gene Cassette Arrays

Integron carriage by 36 epidemiologically unrelated Acinetobacter baumannii isolates collected over an 11-year period from patients in six different Italian hospitals was investigated. Sixteen type 1 integron-positive isolates (44%) were found, 13 of which carried the same array of cassettes, i.e., aacC1, orfX, orfX′, and aadA1a. As ribotype analysis of the isolates demonstrated a notable genetic diversity, horizontal transfer of the entire integron structure or ancient acquisition was hypothesized

Endemic Carbapenem-resistant Pseudomonas aeruginosa with Acquired Metallo-β-lactamase Determinants in European Hospital

Acquired metallo-β-lactamases (MBLs) can confer broad-spectrum β-lactam resistance (including carbapenems) not reversible by conventional β-lactamase inhibitors and are emerging resistance determinants of remarkable clinical importance. In 2001, multidrug-resistant Pseudomonas aeruginosa carrying blaVIM MBL genes were found to be widespread (approximately 20% of all P. aeruginosa isolates and 70% of the carbapenem-resistant isolates) at Trieste University Hospital. Clonal diversity and heterogeneity of resistance determinants (either blaVIM-1-like or blaVIM-2-like) were detected among MBL producers. This evidence is the first that acquired MBLs can rapidly emerge and establish a condition of endemicity in certain epidemiologic settings

Solar H2generation via ethanol photoreforming on \u3b5-Fe2O3nanorod arrays activated by Ag and Au nanoparticles

Earth-abundant, non toxic and cheap Fe2O3 can be used as photocatalyst for sustainable hydrogen production from bio-ethanol aqueous solutions, under sunlight irradiation and without the application of any external electrical bias. To this aim, supported materials are not only technologically more appealing than powders, but also of key importance to develop photoactive and stable Fe2O3-based nanostructured photocatalysts. Here we demonstrated that, while bulk Fe2O3 is unsuitable for solar hydrogen evolution, nanostructured iron(III) oxide polymorphs show promising photoactivity. In particular, a hydrogen yield of 20 mmol h 121 m 122 was obtained on \u3b5-Fe2O3 nanorod arrays supported on Si(100) under simulated sunlight irradiation, mainly due to UV solar photon absorption. The functionalization with partially oxidized Ag nanoparticles resulted in a positive performance improvement upon selective irradiation with the UV portion of the solar spectrum. Conversely, the incorporation of Au nanoaggregates into \u3b5-Fe2O3 enabled to obtain a significant H2 production even under sole Vis light

Solar H2 generation via ethanol photoreforming on \u3b5-Fe2O3 nanorod arrays activated by Ag and Au nanoparticles

Earth-abundant, non toxic and cheap Fe2O3 can be used as photocatalyst for sustainable hydrogen production from bio-ethanol aqueous solutions, under sunlight irradiation and without the application of any external electrical bias. To this aim, supported materials are not only technologicallymore appealing than powders, but also of key importance to develop photoactive and stable Fe2O3-based nanostructured photocatalysts. Here we demonstrated that, while bulk Fe2O3 is unsuitable for solar hydrogen evolution, nanostructured iron(III) oxide polymorphs showpromising photoactivity. In particular, a hydrogen yield of 20mmol h-1m-2 was obtained on epsilon-Fe2O3 nanorod arrays supported on Si(100) under simulated sunlight irradiation, mainly due to UV solar photon absorption. The functionalization with partially oxidized Ag nanoparticles resulted in a positive performance improvement upon selective irradiation with the UV portion of the solar spectrum. Conversely, the incorporation of Au nanoaggregates into epsilon-Fe2O3 enabled to obtain a significant H2 production even under sole Vis light