No abstract

No abstract

Objectives A seroprevalence study of SARS-CoV-2 was conducted in a high-incidence area located in North-eastern Italy. Methods All citizens above ten years of age resident in 5 municipalities of the Autonomous Province of Trento, with the highest incidence of COVID-19 cases, were invited to participate in the study. Overall, among 6098 participants, 6075 sera and a standardized questionnaire administered face-to-face were collected between May 5 and 15, 2020 and examined. Symptomatic individuals and their family contacts were tested by RT-PCR. Anti-SARS-CoV-2 antibodies were detected using an Abbott SARS-CoV-2 IgG assay which was performed on the Abbott Architect i2000SR automated analyzer. Seroprevalence was calculated as the proportion of positive people on the total number of tested. A multivariable logistic regression model was performed to assess the relationship between seropositive versus seronegative individuals for a set of explanatory variables. Results A total of 1402 participants were positives for IgG antibodies against SARS-CoV-2, with a prevalence of 23.1% (1402/6075). The highest prevalence was found in the age class 40-49 years. Overall, 34.4% (2096/6098) of the participants reported at least 1 symptom. The ratio between reported cases identified by molecular test and those resulting seropositive was 1:3, with a maximum ratio of about 1:7 in the age group <20 years and a minimum around 1:1 in those >70 years old. The infection fatality rate was 2.5% (35/1402). Among the symptoms, anosmia and ageusia were strongly associated with seropositivity. Conclusions The estimated seroprevalence of 23% was 3-fold higher than the number of cases reported in the COVID-19 Integrated Surveillance data in the study area. This may be explained in part by a relatively high number of individuals presenting mild or no illness, especially of younger age, and/or who did not seek medical care or testing, but who may contribute to virus transmission in the community.

The meningococcal antigen typing system (MATS) sandwich enzyme-linked immunosorbent assay (ELISA) was designed to measure the immunologic cross-reactivity and quantity of antigens in target strains of a pathogen. It was first used to measure the factor H-binding protein (fHbp), neisserial adhesin A (NadA), and neisserial heparin-binding antigen (NHBA) content of serogroup B meningococcal (MenB) isolates relative to a reference strain, or "relative potency" (RP). With the PorA genotype, the RPs were then used to assess strain coverage by 4CMenB, a multicomponent MenB vaccine. In preliminary studies, MATS accurately predicted killing in the serum bactericidal assay using human complement, an accepted correlate of protection for meningococcal vaccines. A study across seven laboratories assessed the reproducibility of RPs for fHbp, NadA, and NHBA and established qualification parameters for new laboratories. RPs were determined in replicate for 17 MenB reference strains at laboratories A to G. The reproducibility of RPs among laboratories and against consensus values across laboratories was evaluated using a mixed-model analysis of variance. Interlaboratory agreement was very good; the Pearson correlation coefficients, coefficients of accuracy, and concordance correlation coefficients exceeded 99%. The summary measures of reproducibility, expressed as between-laboratory coefficients of variation, were 7.85% (fHbp), 16.51% (NadA), and 12.60% (NHBA). The overall withinlaboratory measures of variation adjusted for strain and laboratory were 19.8% (fHbp), 28.8% (NHBA), and 38.3% (NadA). The MATS ELISA was successfully transferred to six laboratories, and a further laboratory was successfully qualified.

BackgroundPreliminary results suggest that pertussis infection might be considered in infants during a seasonal respiratory syncytial virus (RSV) outbreak.MethodsIn order to analyze clinical features and laboratory findings in infants with pertussis hospitalized for acute respiratory symptoms during a seasonal RSV outbreak, we conducted a retrospective single-center study on 19 infants with pertussis (6 boys; median age 72 days) and 19 matched controls (RSV-bronchiolitis), hospitalized from October 2008 to April 2010. B. pertussis and RSV were detected from nasopharyngeal washes with Real Time-PCR.ResultsInfants with pertussis were less often breastfeed than infants with RSV bronchiolitis (63.2% vs 89.5%; p <0.06). Clinically, significantly fewer infants with pertussis than controls had more episodes of whooping cough (63.2% vs 0.0%; p < 0.001) and also less frequently fever at admission (15.8% vs 68.4%; p <0.01), apnea (52.6% vs 10.5%; p <0.006), and cyanosis (52.6% vs 10.5%; p < 0.006). Infants with pertussis had more often no abnormal chest sounds on auscultation than infants with RSV bronchiolitis (0% vs 42,1%; p < 0.005). The absolute blood lymphocyte and eosinophil counts were higher in infants with B. pertussis than in controls with bronchiolitis (23886 ± 16945 vs 10725 ± 4126 cells/mm3, p < 0.0001 and 13.653 ± 10.430 vs 4.730 ± 2.400 cells/mm3, p < 0.001). The molecular analysis of 2 B. pertussis isolates for ptxA1, ptxP3, and prn2 genes showed the presence of gene variants.ConclusionsWhen infants are hospitalized for acute respiratory symptoms, physicians should suspect a pertussis infection, seek for specific clinical symptoms, investigate lymphocyte and eosinophil counts and thus diagnose infection early enough to allow treatment.

Onconase (ONC), a member of the RNase A superfamily extracted from oocytes of Rana pipiens, is an effective cancer killer. It is currently used in treatment of various forms of cancer. ONC antitumor properties depend on its ribonucleolytic activity that is low in comparison with other members of the superfamily. The most damaging side effect from Onconase treatment is renal toxicity, which seems to be caused by the unusual stability of the enzyme. Therefore, mutants with reduced thermal stability and/or increased catalytic activity may have significant implications for human cancer chemotherapy. In this context, we have determined the crystal structures of two Onconase mutants (M23L-ONC and C87S,des103-104-ONC) and performed molecular dynamic simulations of ONC and C87S,des103-104-ONC with the aim of explaining on structural grounds the modifications of the activity and thermal stability of the mutants. The results also provide the molecular bases to explain the lower catalytic activity of Onconase compared with RNase A and the unusually high thermal stability of the amphibian enzyme.Ribonucleases are widely found in living organisms and have been proposed to function in RNA metabolism and gene expression (1). Several ribonucleases have been isolated from organs of various animals and have been well characterized. Bovine pancreatic ribonuclease (RNase A) 1 is the most studied member of the family (2). It has been used as a model for the study of the fundamental aspects of protein structure and function (2, 3). Several members of the RNase A superfamily exhibit additional biological functions in connection with their intrinsic ribonucleolytic activities (4, 5). In humans, eosinophil-derived neurotoxin and eosinophil cationic protein (6) exert neurotoxicity as well as antiparasitic activity (7). Bovine seminal ribonuclease (BS-RNase) has been found to induce apoptosis of human thyroid carcinoma cell lines (8, 9). Onconase (ONC) from Rana pipiens is cytotoxic (10) and cytostatic to several tumor lines and is currently in phase III clinical trials for the treatment of malignant mesothelioma (8,11,12). ONC shares 30% of identity with the sequence of RNase A, and its three-dimensional structure exhibits a highly conserved ribonuclease-like topology (13), which comprises a characteristic V-shaped ␤-sheet motif surrounded by three ␣-helices. Differences are mainly localized in the loop regions, which are significantly shorter in ONC, and at the C terminus where a disulfide bond, unique to amphibian ribonucleases, tethers the C-terminal residue Cys 104 to Cys 87 located in one strand of the ␤-sheet (13). Another distinct property of ONC is the presence of an N-terminal pyroglutamate (Pyr 1 ), which folds back against the N-terminal helix (13). The overall active site architecture closely resembles that of RNase A and includes His 10 , Lys 31 , and His 97 , which form the catalytic triad corresponding to His 12 , Lys 41 , and His 119 , respectively, of the pancreatic enzyme. Despite this similarity and the activating effe...

BackgroundConfidence in any diagnostic and antimicrobial susceptibility testing data is provided by appropriate and regular quality assurance (QA) procedures. In Europe, the European Gonococcal Antimicrobial Susceptibility Programme (Euro-GASP) has been monitoring the antimicrobial susceptibility in Neisseria gonorrhoeae since 2004. Euro-GASP includes an external quality assessment (EQA) scheme as an essential component for a quality-assured laboratory-based surveillance programme. Participation in the EQA scheme enables any problems with the performed antimicrobial susceptibility testing to be identified and addressed, feeds into the curricula of laboratory training organised by the Euro-GASP network, and assesses the capacity of individual laboratories to detect emerging new, rare and increasing antimicrobial resistance phenotypes. Participant performance in the Euro-GASP EQA scheme over a 10 year period (2007 to 2016, no EQA in 2013) was evaluated.MethodsAntimicrobial susceptibility category and MIC results from the first 5 years (2007–2011) of the Euro-GASP EQA were compared with the latter 5 years (2012–2016). These time periods were selected to assess the impact of the 2012 European Union case definitions for the reporting of antimicrobial susceptibility.ResultsAntimicrobial susceptibility category agreement in each year was ≥91%. Discrepancies in susceptibility categories were generally because the MICs for EQA panel isolates were on or very close to the susceptibility or resistance breakpoints. A high proportion of isolates tested over the 10 years were within one (≥90%) or two (≥97%) MIC log2 dilutions of the modal MIC, respectively. The most common method used was Etest on GC agar base. There was a shift to using breakpoints published by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) in the latter 5 years, however overall impact on the validity of results was limited, as the percentage categorical agreement and MIC concordance changed very little between the two five-year periods.ConclusionsThe high level of comparability of results in this EQA scheme indicates that high quality data are produced by the Euro-GASP participants and gives confidence in susceptibility and resistance data generated by laboratories performing decentralised testing.

The emergence of Neisseria gonorrhoeae isolates displaying resistance to antimicrobial agents is a major public health concern and a serious issue related to the occurrence of further untreatable gonorrhea infections. A retrospective analysis on 1,430 N.