1,214 research outputs found
Extended-spectrum ß-lactamase, AmpC-producing, and fluoroquinolone-resistant Escherichia coli in retail broiler chicken meat, Italy
Background: Globally, antimicrobial drug-resistant Escherichia coli is among the most common etiological agents of invasive disease in humans. In Europe, increasing proportions of infections due to third-generation cephalosporins and/or fluoroquinolone-resistant extraintestinal pathogenic E. coli (ExPEC) strains are reported. E. coli from poultry are those more closely linked to human E. coli, but lack of reliable data makes it difficult to assess the attributable risk of different food sources. In the present study, our objective was to investigate the antimicrobial resistance profile, phylogenetic background, and virulence factors of E. coli isolates from broiler chicken meat sold at retail in Palermo, Italy. Materials and Methods: Isolation of multidrug resistant (MDR) E. coli was performed during April-December 2013 on a total of 163 chicken meat samples. Susceptibility to a panel of nine antimicrobial agents was determined. PCR assays were carried out to detect extended-spectrum β-lactamase (ESBL), plasmid-mediated AmpC β-lactamase, and plasmid-mediated quinolone resistance (PMQR) genes, phylogenetic group, and ExPEC-associated traits. A single nucleotide polymorphism (SNP) PCR was done to detect E. coli sequence type (ST)131. Results: One hundred thirty-four isolates from 109 meat samples were MDR. B1 was the most prevalent phylogenetic group (47.8%), followed by groups D (25.4%), A (22.3%), and B2 (4.5%). ESBLs and AmpC β-lactamases were detected by PCR in 132 (98.5%) and 15 (11.2%) isolates. PMQR determinants were detected in 122 (91%) isolates. Twenty-two MDR isolates met the molecular definition of ExPEC. SNP-PCR results confirmed that four B2 isolates were ST131. Enterobacterial Repetitive Intergenic Consensus sequence-PCR analysis showed a large heterogeneity with 55 unique profiles and 31 clusters including 2-4 isolates. Conclusions: An alarmingly high prevalence of MDR E. coli from broiler chicken meat is evident in our geographic area. The ongoing use of antimicrobial drugs in livestock should be urgently restricted, particularly in the poultry sector
Plant Conservation Centres in Sicily: The ‘Valle Maria’ Regional Centre (Godrano, Palermo) and the case study of the rare Centaurea erycina (Asteraceae).
The role of the ‘Valle Maria’ Regional Centre and its activity in plant conservation thank to the collaboration with the University of Palermo, Dept. STEBICEF is discussed. The case study on propagation of Centaurea erycina, a narrow Sicilian endemic is presented
Elucidation of role of graphene in catalytic designs for electroreduction of oxygen
Graphene is, in principle, a promising material for consideration as
component (support, active site) of electrocatalytic materials, particularly
with respect to reduction of oxygen, an electrode reaction of importance to
low-temperature fuel cell technology. Different concepts of utilization,
including nanostructuring, doping, admixing, preconditioning, modification or
functionalization of various graphene-based systems for catalytic
electroreduction of oxygen are elucidated, as well as important strategies to
enhance the systems' overall activity and stability are discussed
Evaluation of Reduced-Graphene-Oxide Aligned with WO3-Nanorods as Support for Pt Nanoparticles during Oxygen Electroreduction in Acid Medium
Hybrid supports composed of chemically-reduced graphene-oxide-aligned with
tungsten oxide nanowires are considered here as active carriers for dispersed
platinum with an ultimate goal of producing improved catalysts for
electroreduction of oxygen in acid medium. Here WO3 nanostructures are expected
to be attached mainly to the edges of graphene thus making the hybrid structure
not only highly porous but also capable of preventing graphene stacking and
creating numerous sites for the deposition of Pt nanoparticles. Comparison has
been made to the analogous systems utilizing neither reduced graphene oxide nor
tungsten oxide component. By over-coating the reduced-graphene-oxide support
with WO3 nanorods, the electrocatalytic activity of the system toward the
reduction of oxygen in acid medium has been enhanced even at the low Pt loading
of 30 microg cm-2. The RRDE data are consistent with decreased formation of
hydrogen peroxide in the presence of WO3. Among important issues are such
features of the oxide as porosity, large population of hydroxyl groups, high
Broensted acidity, as well as fast electron transfers coupled to unimpeded
proton displacements. The conclusions are supported with mechanistic and
kinetic studies involving double-potential-step chronocoulometry as an
alternative diagnostic tool to rotating ring-disk voltammetry.Comment: arXiv admin note: text overlap with arXiv:1805.0315
Assessment of contamination of Salmonella spp. in imported black pepper and sesame seed and salmonella inactivation by gamma irradiation
This study shows the frequency of seeds samples contaminated by Salmonella spp. collected randomly from local markets; on 30 black pepper sample no contaminated sample was found while Salmonella spp. was detected in 3 of 36 (8.3%) analyzed sesame samples; three different serotypes were identified: S. Montevideo, S. Stanleyville e S. Tilene. The efficacy of gamma irradiation to inactivate Salmonella Montevideo in black pepper and sesame irradiated between 1 and 5 kGy was evaluated. 3 kGy is sufficient to reduce of 3-4 log CFU/g; whereas 5 kGy have been need to reduce 5.5-6 log CFU/g for samples of black pepper and sesame. No statistically significant differences were found between black pepper and sesame
Further characterization of agmatine binding to mitochondrial membranes: involvement of imidazoline I2 receptor.
Agmatine, a divalent diamine with two positive charges at physiological pH, is transported into the matrix of liver mitochondria by an energy-dependent mechanism, the driving force of which is the electrical membrane potential. Its binding to mitochondrial membranes is studied by applying a thermodynamic treatment of ligand-receptor interactions on the analyses of Scatchard and Hill. The presence of two mono-coordinated binding sites S(1) and S(2), with a negative influence of S(2) on S(1), has been demonstrated. The calculated binding energy is characteristic for weak interactions. S(1) exhibits a lower binding capacity and higher binding affinity both of about two orders of magnitude than S(2). Experiments with idazoxan, a ligand of the mitochondrial imidazoline receptor I(2), demonstrate that S(1) site is localized on this receptor while S(2) is localized on the transport system. S(1) would act as a sensor of exogenous agmatine concentration, thus modulating the transport of the amine by its binding to S(2)
PRIMI DATI SUGLI INNESTI DI ABIES NEBRODENSIS (LOJAC.) MATTEI ESEGUITI SU ABETI ESOTICI NELL\u2019AREA DI INDIGENATO (MADONIE)
C2 = PRIMI DATI SUGLI INNESTI DI ABIES NEBRODENSIS (LOJAC.) MATTEI
ESEGUITI SU ABETI ESOTICI NELL\u2019AREA DI INDIGENATO (MADONIE)
R. SCHICCHI, P. BONOMO, M. CANDORE, G. DI NOTO, A. PUCCI, F. TRAPANI, P. MARINO
Dipartimento di Biologia Ambientale e Biodiversit\ue0 dell'Universit\ue0, via Archirafi 38, 90123 Palermo (I)
[email protected]
Abies nebrodensis \ue8 una specie endemica relitta, gravemente minacciata di estinzione, la cui popolazione naturale \ue8 costituita da 30 individui distribuiti discontinuamente in una piccola area del territorio di Polizzi Generosa, all\u2019interno del Parco naturale delle Madonie in Sicilia. La minaccia di estinzione \ue8 dovuta, oltre all'esiguit\ue0 della popolazione, al ridotto numero di piante mature (ventiquattro) e al pericolo di inquinamento genetico incombente. A partire dall\u2019inizio degli anni \u201880 del secolo scorso, infatti, sono stati introdotti nella vicinanze dell\u2019area di indignato individui di abeti esotici (Abies alba Mill., A. cephalonica Loudon, e A. nordmanniana (Stefen) Spach) che, avendo raggiunto la maturit\ue0 sessuale, potrebbero mettere a rischio l\u2019integrit\ue0 genetica della progenie dell\u2019abete locale (Raimondo & Schicchi, 2005). Nell\u2019ambito del progetto \u201cConservazione di Abies nebrodensis e ripristino delle torbiere di Geraci Siculo\u201d, in corso di attuazione da parte dell\u2019Ente Parco delle Madonie, del Dipartimento di Biologia ambientale e Biodiversit\ue0 di Palermo e di altri partners locali, un\u2019azione di salvaguardia prevede l\u2019innesto degli abeti esotici con marze di A. nebrodensis, valorizzando la positiva esperienza effettuata con il progetto Life Natura (1). A tal fine, nel periodo compreso tra la terza decade di aprile e la seconda decade di maggio sono stati effettuati circa 350 innesti in contrada Comunello, nel territorio di Isnello. Le marze sono state prelevate da individui maturi di A. nebrodensis di oltre 30 anni di et\ue0, introdotti nelle opere di ripopolamento che, in seguito ai risultati delle analisi genetiche, sono geneticamente correlati agli esemplari della popolazione naturale. Gli innesti sono stati eseguiti a spacco ma soprattutto a corona, previa capitozzatura dei soggetti di A. alba e A. cephalonica, a un\u2019altezza di circa 2 m per evitare possibili danneggiamenti da parte del bestiame. Nei soggetti sono stati, comunque, rilasciati temporaneamente alcuni palchi che, continuando a svolgere le normali funzioni vitali, agevoleranno l\u2019attecchimento delle marze. Queste ultime sono state opportunamente sagomate e inserite tra la corteccia e il legno sia nel fusto capitozzato che in alcuni rami laterali. Esse sono state tenute strettamente aderenti ai soggetti tramite nastro adesivo e protette da due sacchetti, rispettivamente di polietilene e di carta, per creare condizioni micro-climatiche ottimali alla sopravvivenza delle marze. Dalla terza decade di maggio \ue8 iniziato, con cadenza settimanale, il monitoraggio degli innesti e la foratura, ove necessario, del sacchetto di plastica per eliminare l\u2019umidit\ue0 in eccesso. Dopo 40 giorni \ue8 stato possibile constatare che oltre il 90% degli innesti \ue8 attecchito. Anche alcuni innesti eseguiti a scopo sperimentale su Pseudotsuga menziesii Franco sono vitali. Durante la fine di luglio e agosto si prevede una graduale scopertura delle marze. Gli esiti di questa azione, tuttavia, potranno essere valutati compiutamente all\u2019inizio della prossima primavera. La tecnica dell\u2019innesto riveste notevole importanza poich\ue9 permette di eliminare o ridurre una delle minacce pi\uf9 consistenti a carico della popolazione naturale di A. nebrodensis, trasformando la stessa in un punto di forza nell\u2019ambito della strategia di conservazione della specie. Essa, infatti, potr\ue0 contribuire a incrementare la popolazione dell\u2019endemico A. nebrodensis, valorizzando come portainnesti piante che se non abbattute costituirebbero un serio pericolo per la conservazione dell\u2019abete delle Madonie.
Raimondo F. M., Schicchi R., 2005. Rendiconto sul progetto LIFE Natura n\ub0 LIFE2000NAT/IT/7228 \u201cConservazione in situ ed ex situ di Abies nebrodensis (Lojac.) Mattei\u201d. Tipolitografia Luxograph, Palermo
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