46 research outputs found

    Genealogical typing of Neisseria meningitidis

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    Despite the increasing popularity of multilocus sequence typing (MLST), the most appropriate method for characterizing bacterial variation and facilitating epidemiological investigations remains a matter of debate. Here, we propose that different typing schemes should be compared on the basis of their power to infer clonal relationships and investigate the utility of sequence data for genealogical reconstruction by exploiting new statistical tools and data from 20 housekeeping loci for 93 isolates of the bacterial pathogen Neisseria meningitidis. Our analysis demonstrated that all but one of the hyperinvasive isolates established by multilocus enzyme electrophoresis and MLST were grouped into one of six genealogical lineages, each of which contained substantial variation. Due to the confounding effect of recombination, evolutionary relationships among these lineages remained unclear, even using 20 loci. Analyses of the seven loci in the standard MLST scheme using the same methods reproduced this classification, but were unable to support finer inferences concerning the relationships between the members within each complex

    Molecular epidemiology of meningococcal disease in England and Wales 1975–1995, before the introduction of serogroup C conjugate vaccines

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    A comprehensive meningococcal vaccine is yet to be developed. In the absence of a vaccine that immunizes against the serogroup B capsular polysaccharide, this can only be achieved by targeting subcapsular antigens, and a number of outer-membrane proteins (OMPs) are under consideration as candidates. A major obstacle to the development of such a vaccine is the antigenic diversity of these OMPs, and obtaining population data that accurately identify and catalogue these variants is an important component of vaccine design. The recently proposed meningococcal molecular strain-typing scheme indexes the diversity of two OMPs, PorA and FetA, that are vaccine candidates, as well as the capsule and multilocus sequence type. This scheme was employed to survey 323 meningococci isolated from invasive disease in England and Wales from 1975 to 1995, before the introduction of meningococcal conjugated serogroup C polysaccharide vaccines in 1999. The eight-locus typing scheme provided high typeability (99.4 %) and discrimination (Simpson's diversity index 0.94–0.99). The data showed cycling of meningococcal genotypes and antigenic types in the absence of planned interventions. Notwithstanding high genetic and antigenic diversity, most of the isolates belonged to one of seven clonal complexes, with 11 predominant strain types. Combinations of PorA and FetA, chosen on the basis of their prevalence over time, generated vaccine recipes that included protein variants found in 80 % or more of the disease isolates for this time period. If adequate immune responses can be generated, these results suggest that control of meningococcal disease with relatively simple protein component vaccines may be possible

    Workshop on Regulatory Preparedness for Innovation in Nanotechnology

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    This report summarises the presentations and discussions at the first NanoReg2 Workshop on Regulatory Preparedness for Innovation in Nanotechnology held in Ispra, Italy 5 to 6 October 2017 and attended by approximately 60 regulators, industry representatives and other stakeholders. NanoReg2 is a European Union (EU) Horizon 2020 project. At the workshop, Regulatory Preparedness was defined as the regulators' timely awareness of innovations and the regulator's actions to check whether present legislation covers all safety aspects of each innovation, including initiating revision of the legislation as appropriate. Regulatory Preparedness, and Safe-by-Design (SbD) jointly constitute the NanoReg2 Safe Innovation Approach (SIA) for developing innovative products based on nanotechnology. The workshop aimed to gather views and identify current practices in regulatory work on safety of innovative products, tools already in use or needed, and potential difficulties in implementing Regulatory Preparedness in the EU. Presentations addressed the current state of the safety of nanotechnology innovation. The viewpoints included the regulatory framework, the principles behind it and the agencies and authorities enforcing it; nanosafety research projects and their support system (e.g. the current EU Horizon 2020 Framework Programme); national nanosafety initiatives; and the development of tools, such as foresight tools and harmonised test guidelines by the OECD for data generation. The workshop served to generate ideas for achieving Regulatory Preparedness. The participants recognised that while regulators deal with the safety of innovations, only few systematic approaches to this work exist. Some innovative products may reach the market before their safety has been appropriately assessed, as illustrated by RAPEX, the Rapid Exchange of Information System. A continuous and proactive combination of interconnected activities was considered to be required for ensuring Regulatory Preparedness. Thus, anticipation, e.g. horizon scanning, was seen as important, as was communication between regulators, innovators (industry) and other stakeholders. Regulators need to become aware of innovative products under development to ensure that the legislation and methods for safety assessment are available and adequate. Innovators must be aware of regulatory requirements and their likely development. This mutual awareness helps to develop safe products and to avoid delays or other problems in obtaining market approval. Awareness can be achieved through communication, which requires trust, e.g. promoted via "trusted environments" for confidential inquiries and information sharing. Furthermore, regulators need early access to the existing information and data relevant to safety assessment of innovative products to provide timely guidance and advice to Industry as well as to develop strategies for dealing with uncertainty, e.g. by applying the precautionary principle. Regulatory Preparedness was discussed as part of the SIA, and a "road map" of actions was suggested and outlined. The workshop has thus contributed towards acceptance of implementing Regulatory Preparedness for innovation in nanotechnology through the participation of a variety of stakeholders. This paves the way for a better dialogue among stakeholders in a fast economic development cycle, where it is even more important to quickly identify emerging needs for new approaches to regulatory issues for innovationJRC.F.2-Consumer Products Safet
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