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While polycarboxylates and hydroxyl-acid complexes have long been known to be photoactive, simple carboxylate complexes which lack a significant LMCT band are not typically strongly photoactive. Hence, it was somewhat surprising that a series of reports demonstrated that materials synthesized from iron(III) and polysaccharides such as alginate (poly[guluronan-co-mannuronan]) or pectate (poly[galacturonan]) formed photoresponsive materials that convert from hydrogels to sols under the influence of visible light. These materials have numerous potential applications in areas such as photopatternable materials, materials for controlled drug delivery, and tissue engineering. Despite the near-identity of the functional units in the polysaccharide ligands, the reactivity of iron(III) hydrogels can depend on the configuration of some chiral centers in the sugar units and in the case of alginate the guluronate to mannuronate block composition, as well as pH. Here, using temperature- and field-dependent transmission Mössbauer spectroscopy, we show that the dominant iron compound detected for both the alginate and pectate gels displays features typical of a polymeric (Fe3+O6) system. The Mössbauer spectra of such systems are strongly dependent on temperature, field, size, and crystallinity, indicative of superparamagnetic relaxation of magnetically ordered nanoparticles. Pectate and alginate hydrogels differ in the size distribution of the iron oxyhydroxy nanoparticles, suggesting that in general smaller nanoparticles are more reactive. Potential biological implications of these results are also discussed.

We develop and test a model that envisages work engagement in public services as determined by interactions with supervisor and co-workers. Specifically, we apply the framework of Social Exchange Theory to explore the impact of Leader-Member exchange (LMX) and Team-Member exchange (TMX) on Work Engagement in the provision of health care in public hospitals. Our investigation suggests that both LMX and TMX represent significant factors associated with work engagement among the hospital medical staff. [ABSTRACT FROM AUTHOR]

AbstractMolecular epidemiology at local scale in Sicily (Italy) of ampicillin resistance in Salmonellaspp. isolates from municipal wastewater (n= 64) and clinical specimens (n= 274) is described in comparison with previously examined Escherichia coliisolates (n= 273) from wastewater. High prevalence of antibiotic resistance (28.9%) with highest resistance rates against ampicillin (22.7%) was observed in E. coliisolates. Different resistance rates were observed in Salmonellaaccording to the serovars, with prevalences of the same order in both wastewater and clinical isolates belonging to the same serovar (e.g., 91.7% ampicillin resistance in wastewater isolates vs. 70.8% in clinical isolates of the Salmonellaserovar Typhimurium and 0% ampicillin resistance in both wastewater and clinical isolates of the Salmonellaserovar Enteritidis). The β-lactam resistance gene blaTEMwas present in both wastewater and clinical Salmonellaspp. isolates, with the exception of Salmonella entericaserovar Typhimurium isolates with a typical six-drug resistance pattern AmpChlSulTeStrSp that had the blaPSE-1gene. The blaTEMgene was present in all the E. coliisolates but one had the blaSHVgene. Several E. coliand some Salmonellaisolates were positive for class 1 integrons with variable regions of 1.0 or 1.5 kb containing aadA1, dfrA17-aadA5, or dfrA1-aadA1gene cassettes, whereas Salmonellaserovar Typhimurium isolates with the six-drug resistance pattern were positive for both 1.0 and 1.2 kb integrons. Polymerase chain reaction replicon typing demonstrated the presence of multireplicon resistance plasmids in several isolates of E. coli, containing two to four of the replicons IncF, IncI1, IncFIA, and IncFIB, whereas other isolates showed resistance plasmids with only IncF, IncP, or IncK replicons. Replicon IncI1 was detected in one Salmonellaisolate, whereas other isolates belonging to different serovars had IncN replicons. Analysis of isolates from wastewater can be a useful epidemiologic tool to monitor the prevalence of antibiotic resistance and genetic elements related to antibiotic resistance in Salmonellaclones circulating in the human population.

Objective:To evaluate the economical impact of universal immunisation of children aged < 1 year against Hib based on three doses of Haemophilus influenzaetype b (Hib) conjugated vaccine in Italy.

ABSTRACTTwenty-one Escherichia coliO157:H7 strains isolated in northern Italy from sporadic cases of hemolytic-uremic syndrome and from cattle and food were characterized by virulence gene analysis, pulsed-field gel electrophoresis (PFGE) of XbaI-digested DNA, enterobacterial repetitive intergenic consensus (ERIC) sequence-based PCR (ERIC-PCR), and antibiotic resistance patterns and compared to 18 strains isolated in France from human cases of diarrhea, cattle, and the environment. Strains isolated in Sicily (southern Italy) from a local farm (one strain) and from calves just imported from France (11 strains) and Spain (six strains) were also typed. Whereas the eaeand hlyAgenes were always detected, Shiga toxin gene (stx) analysis showed some differences related to geographic areas. Isolates from northern Italy showed a high frequency of stx1and stx2, while strains isolated in France and from French and Spanish calves imported to Sicily more frequently possessed the stx2cgene. The majority of the strains isolated in northern Italy were also resistant to one or more antibiotics, while most of the strains isolated in France and Sicily were fully susceptible. ERIC-PCR analysis was not able to differentiate the strains. PFGE typing after XbaI DNA digestion produced a total of 54 distinct restriction endonuclease digestion profiles (REDPs) among the 57 strains. Phylogenetic analysis was unable to cluster REDPs according to geographic origin. All epidemiologically related isolates showed either identical or =91% similar REDPs. Our findings suggest a peculiar circulation of antibiotic-resistant, genetically unrelated strains in northern Italy.

ABSTRACTFrom 1984 to 1999, we collected 31 isolates of the rare serovar Salmonella bongori48:z35:- in southern Italy. Twenty-four of the isolates were from cases of acute enteritis in humans. Pulsed-field gel electrophoresis analysis showed that all but one of our isolates were at least 80% similar. Our findings suggest that genetically related S. bongori48:z35:- strains are endemically circulating in southern Italy.

AbstractAgrobacteriumisolates from intravenous catheters of three hospitalized patients were initially identified as A. tumefaciens,but inability to produce 3-ketolactose revealed that two of them were A. vitis.However, rDNA analysis correlated all of the isolates to A. tumefaciens.Pulsed-field gel electrophoresis analysis ascertained the nosocomial transmission of the infection.