Knowledge, attitudes, and practices of influenza and pneumococcal vaccines among agricultural workers: Results of an Italian a cross-sectional study

Background: Working age is increasing across Europe. Seasonal influenza (SID) and pneumococcal disease (PND) immunization programmes might be successfully implemented at the workplace. We conducted a cross-sectional survey among to assess SID and PND vaccine status, as well as knowledge, attitudes and practices (KAP) in a representative sample of agricultural workers (AWs) aged ≥55 years in North-Eastern Italy. Methods: A structured questionnaire was administered in person by trained personnel. Bivariate and multivariate logistic regression analyses were carried out to identify behavioral and work-related factors associated with SID and PND vaccine uptake. Results: Among 707 participants, 238 were aged 55 years or more (33.7% of total). Of them, 39.1% had an up-to-date immunization status towards influenza, and 17.6% towards pneumococcus. Factors associated with inadequate immunization were doubts about influenza vaccine safety (40.0%) and the confidence in natural immunity towards pneumococcus (30.8%). Attitude towards vaccinations was somehow favorable in 44.5% of participants for SID, and 37.8% for PND. Overall, 37.4% and 21.8% workers were aware of national recommendations on SID and PND immunization, respectively. This factor was characterized as a significant predictor for SID vaccination (multivariated Odds Ratio, OR 32.688 95%CI 12.015-88.930), as well as the perception of SID as a severe disease (OR 7.539 95%CI 3.312-17.164), and the perceived value of preventing new infections (OR 3.215 95%CI 1.205-8.578). A somehow favorable attitude towards vaccinations was the main predictor (OR 39.214 95%CI 10.179-151.1) for PND vaccination. Conclusions: Our study indicates that older workers lack appropriate knowledge of national recommendations and correct risk perception of SID and PND infections, but also vaccines’ side effects. As the latter has been recognized as predictive factor for SID vaccination, our results stress the importance for tailored informative interventions in the workplaces aimed to increase risk perception and vaccine acceptance. (www.actabiomedica.it)

Sofosbuvir-based therapies in genotype 2 hepatitis C virus cirrhosis: A real-life experience with focus on ribavirin dose

This study aimed to investigate the efficacy and safety of sofosbuvir-based therapies for the treatment of cirrhosis from hepatitis C virus (HCV) genotype 2 infection. Data of all consecutive HCV genotype 2 cirrhotic patients who started sofosbuvir-based treatments between January 2015 and March 2017 in eight Italian tertiary hospitals were collected retrospectively. Overall, 273 patients (Child A: 94.5%) were enrolled. In the 194 subjects treated with sofosbuvir/ribavirin, median initial ribavirin dosage was 13.9 mg/kg/day, and therapy duration was 16 weeks. Sustained virological response (SVR) rates were 93.8% in intention-to-treat (ITT) and 95.3% in per-protocol (PP) analyses for the 129 treatment-naïve patients, and 96.9% (ITT) and 98.4% (PP) for the 65 treatment-experienced subjects. Adverse events were reported in 142 patients (73.2%), but only 1.5% discontinued treatment. Eighty-eight subjects with treatment-induced anemia (mild: 34.5%, moderate: 7.7%, severe: 3.1%) had to reduce ribavirin dosage, but SVR rates were comparable to the weight-based dose group, both in ITT (95.4% and 94.3%) and PP (97.7% and 95.2%) analyses, respectively. Moreover, ITT and PP SVR rates were similar between shorter (<20 weeks) (94.1% and 96.0%, respectively) and prolonged (≥20 weeks) regimens (95.7% and 96.7%, respectively). SVR rates in the 79 subjects treated with sofosbuvir/daclatasvir (without ribavirin) were similar (ITT: 96.2%; PP: 97.4%, respectively), without de novo/worsening anemia. In conclusion, in a real-life study centered on genotype 2 patients with well-compensated cirrhosis, sofosbuvir-based regimens were associated with good SVR and tolerability rates, regardless of previous antiviral treatments, without a significant impact of on treatment ribavirin dose reductions

Identification of the ribosome binding sites of translation initiation factor IF3 by multidimensional heteronuclear NMR spectroscopy

Titrations of Escherichia coli translation initiation factor IF3, isotopically labeled with 15N, with 30S ribosomal subunits were followed by NMR by recording two-dimensional (15N,1H)-HSQC spectra. In the titrations, intensity changes are observed for cross peaks belonging to amides of individual amino acids. At low concentrations of ribosomal subunits, only resonances belonging to amino acids of the C-domain of IF3 are affected, whereas all those attributed to the N-domain are still visible. Upon addition of a larger amount of 30S subunits cross peaks belonging to residues of the N-terminal domain of the protein are also selectively affected. Our results demonstrate that the two domains of IF3 are functionally independent, each interacting with a different affinity with the ribosomal subunits, thus allowing the identification of the individual residues of the two domains involved in this interaction. Overall, the C-domain interacts with the 30S subunits primarily through some of its loops and a-helices and the residues involved in ribosome binding are distributed rather symmetrically over a fairly large surface of the domain, while the N-domain interacts mainly via a small number of residues distributed asymmetrically in this domain. The spatial organization of the active sites of IF3, emerging through the comparison of the present data with the previous chemical modification and mutagenesis data, is discussed in light of the ribosomal localization of IF3 and of the mechanism of action of this factor

Molecular dissection of translation initiation factor IF2. Evidence for two structural and functional domains.

By means of limited proteolysis of Bacillus stearothermophilus initiation factor IF2 and genetic manipulation of its structural gene, infB, we have been able to produce (or hyperproduce) and purify two polypeptide fragments corresponding to two structurally and functionally separate domains of the protein. The first is the G-domain (approximately 41 kDa), which makes up the central part of the molecule and contains the conserved structural elements found in all GTP/GDP-binding sites of G-proteins. This domain is resistant to proteolysis in the presence of GTP or GDP, retains the capacity to interact with the 50 S subunit, binds weakly to the 30 S subunit, and displays ribosome-dependent GTPase activity with an approximately 2-fold higher Km for GTP and the same Vmax as compared with intact IF2. The second is the C-domain (approximately 24 kDa), which corresponds to the COOH-terminal part of IF2 and constitutes an extraordinarily compact domain containing the fMet-tRNA binding site of IF2. In spite of its negligible affinity for the ribosomes, the C-domain weakly stimulates the ribosomal binding of fMet-tRNA, presumably by affecting the conformation of the initiator tRNA molecule

Knowledge, attitudes, practices (KAP) of Italian occupational physicians towards tick borne encephalitis

Tick-Borne Encephalitis (TBE) is an occupational health threat with increasing incidence in the geographic area of Italy. Despite this, TBE vaccination rates have ranged from 10% to 40% in Italy, even in at-risk workers. The reasons for this low rate are investigated in this present study of the knowledge, attitudes, and practices of occupational physicians (OP) regarding TBE disease and vaccination in at-risk workers. A total of 229 OP participated in an internet-based survey by completing a structured questionnaire. Adequate general knowledge of TBE disease was found in 58% of OP. Accurate perception of TBE risk in occupational settings was found in 20%. TBE vaccination for at-risk workers was recommended by 19%. Willingness to recommend TBE vaccination was more likely by OP practicing in endemic areas (Odds Ratio 3.10, 95% confidence intervals 1.47-6.55), who knew the existence of the term “arboviruses” (3.10, 1.29-7.44), or exhibited a better understanding of TBE (2.38, 1.11-5.12)-and were positive predictors for promoting TBE vaccine, while acknowledging that TBE as a severe disease was a negative one. Tick-borne disorders in Italy are a still rare (but increasing) occupational health threat, and vaccination gaps for TBE virus may find an explanation in OP incomplete knowledge of evidence-based recommendations

Molecular dissection of translation initiation factor IF2. Evidence for two structural and functional domains.

By means of limited proteolysis of Bacillus stearothermophilus initiation factor IF2 and genetic manipulation of its structural gene, infB, we have been able to produce (or hyperproduce) and purify two polypeptide fragments corresponding to two structurally and functionally separate domains of the protein. The first is the G-domain (approximately 41 kDa), which makes up the central part of the molecule and contains the conserved structural elements found in all GTP/GDP-binding sites of G-proteins. This domain is resistant to proteolysis in the presence of GTP or GDP, retains the capacity to interact with the 50 S subunit, binds weakly to the 30 S subunit, and displays ribosome-dependent GTPase activity with an approximately 2-fold higher Km for GTP and the same Vmax as compared with intact IF2. The second is the C-domain (approximately 24 kDa), which corresponds to the COOH-terminal part of IF2 and constitutes an extraordinarily compact domain containing the fMet-tRNA binding site of IF2. In spite of its negligible affinity for the ribosomes, the C-domain weakly stimulates the ribosomal binding of fMet-tRNA, presumably by affecting the conformation of the initiator tRNA molecule

Ribosomal selection of mRNAs with degenerate initiation triplets

To assess the influence of degenerate initiation triplets on mRNA recruitment by ribosomes, five mRNAs identical but for their start codon (AUG, GUG, UUG, AUU and AUA) were offered to a limiting amount of ribosomes, alone or in competition with an identical AUGmRNA bearing a mutation conferring different electrophoretic mobility to the product. Translational efficiency and competitiveness of test mRNAs toward this AUGmRNA were determined quantifying the relative amounts of the electrophoretically separated wt and mutated products synthesized in vitro and found to be influenced to different extents by the nature of their initiation triplet and by parameters such as temperature and nutrient availability in the medium. The behaviors of AUAmRNA, UUGmRNA and AUGmRNA were the same between 20 and 40°C whereas the GUG and AUUmRNAs were less active and competed poorly with the AUGmRNA, especially at low temperature. Nutrient limitation and preferential inhibition by ppGpp severely affected activity and competitiveness of all mRNAs bearing non-AUG starts, the UUGmRNA being the least affected. Overall, our data indicate that beyond these effects exclusively due to the degenerate start codons within an optimized translational initiation region, an important role is played by the context in which the rare start codons are present

Site-directed mutagenesis and NMR spectroscopic approaches to the elucidation of the structure-function relationships in translation initiation factors IF1 and IF3.

The recent developments in the knowledge of the structure and structure-function relationships of prokaryotic initiation factors IF1 and IF3 obtained in our laboratory by site-directed mutagenesis, biochemical and NMR-spectroscopic approaches are discussed