Suchergebnisse

In the United States, filoviruses (ebolaviruses and marburgviruses) are listed as National Institute of Allergy and Infectious Diseases (NIAID) Category A Priority Pathogens, Select Agents, and Centers for Disease Control and Prevention (CDC) Category A Bioterrorism Agents. In recent months, U.S. biodefense professionals and policy experts have initiated discussions on how to optimize filovirus research in regard to medical countermeasure (ie, diagnostics, antiviral, and vaccine) development. Standardized procedures and reagents could accelerate the independent verification of research results across government agencies and establish baselines for the development of animal models acceptable to regulatory entities, such as the Food and Drug Administration (FDA), while being fiscally responsible. At the root of standardization lies the question of which filovirus strains, variants, or isolates ought to be the prototypes for product development, evaluation, and validation. Here we discuss a rationale for their selection. We conclude that, based on currently available data, filovirus biodefense research ought to focus on the classical taxonomic filovirus prototypes: Marburg virus Musoke in the case of marburgviruses and Ebola virus Mayinga in the case of Zaire ebolaviruses. Arguments have been made in various committees in favor of other variants, such as Marburg virus Angola, Ci67 or Popp, or Ebola virus Kikwit, but these rationales seem to be largely based on anecdotal or unpublished and unverified data, or they may reflect a lack of awareness of important facts about the variants' isolation history and genomic properties.

Biosafety, biosecurity, logistical, political, and technical considerations can delay or prevent the wide dissemination of source material containing viable virus from the geographic origin of an outbreak to laboratories involved in developing medical countermeasures (MCMs). However, once virus genome sequence information is available from clinical samples, reverse-genetics systems can be used to generate virus stocks de novo to initiate MCM development. In this study, we developed a reverse-genetics system for natural isolates of Ebola virus (EBOV) variants Makona, Tumba, and Ituri, which have been challenging to obtain. These systems were generated starting solely with in silico genome sequence information and have been used successfully to produce recombinant stocks of each of the viruses for use in MCM testing. The antiviral activity of MCMs targeting viral entry varied depending on the recombinant virus isolate used. Collectively, selecting and synthetically engineering emerging EBOV variants and demonstrating their efficacy against available MCMs will be crucial for answering pressing public health and biosecurity concerns during Ebola disease (EBOD) outbreaks.

The task of international expert groups is to recommend the classification and naming of viruses. The ICTV Filoviridae Study Group and other experts have recently established an almost consistent classification and nomenclature for filoviruses. Here, further guidelines are suggested to include their natural genetic variants. First, this term is defined. Second, a template for full-length virus names (such as "Ebola virus H.sapiens-tc/COD/1995/Kikwit-9510621") is proposed. These names contain information on the identity of the virus (e.g., Ebola virus), isolation host (e.g., members of the species Homo sapiens), sampling location (e.g., Democratic Republic of the Congo (COD)), sampling year, genetic variant (e.g., Kikwit), and isolate (e.g., 9510621). Suffixes are proposed for individual names that clarify whether a given genetic variant has been characterized based on passage zero material (-wt), has been passaged in tissue/cell culture (-tc), is known from consensus sequence fragments only (-frag), or does (most likely) not exist anymore (-hist). We suggest that these comprehensive names are to be used specifically in the methods section of publications. Suitable abbreviations, also proposed here, could then be used throughout the text, while the full names could be used again in phylograms, tables, or figures if the contained information aids the interpretation of presented data. The proposed system is very similar to the well-known influenzavirus nomenclature and the nomenclature recently proposed for rotaviruses. If applied consistently, it would considerably simplify retrieval of sequence data from electronic databases and be a first important step toward a viral genome annotation standard as sought by the National Center for Biotechnology Information (NCBI). Furthermore, adoption of this nomenclature would increase the general understanding of filovirus-related publications and presentations and improve figures such as phylograms, alignments, and diagrams. Most importantly, it would counter the increasing ...

In 2014, Ebola virus (EBOV) was identified as the etiological agent of a large and still expanding outbreak of Ebola virus disease (EVD) in West Africa and a much more confined EVD outbreak in Middle Africa. Epidemiological and evolutionary analyses confirmed that all cases of both outbreaks are connected to a single introduction each of EBOV into human populations and that both outbreaks are not directly connected. Coding-complete genomic sequence analyses of isolates revealed that the two outbreaks were caused by two novel EBOV variants, and initial clinical observations suggest that neither of them should be considered strains. Here we present consensus decisions on naming for both variants (West Africa: "Makona", Middle Africa: "Lomela") and provide database-compatible full, shortened, and abbreviated names that are in line with recently established filovirus sub-species nomenclatures. ; This work was funded in part through Battelle Memorial Institute's prime contract with the US National Institute of Allergy and Infectious Diseases (NIAID) under Contract No. HHSN272200700016I. ; http://www.mdpi.com/journal/viruses ; hb2015

In 2014, Ebola virus (EBOV) was identified as the etiological agent of a large and still expanding outbreak of Ebola virus disease (EVD) in West Africa and a much more confined EVD outbreak in Middle Africa. Epidemiological and evolutionary analyses confirmed that all cases of both outbreaks are connected to a single introduction each of EBOV into human populations and that both outbreaks are not directly connected. Coding-complete genomic sequence analyses of isolates revealed that the two outbreaks were caused by two novel EBOV variants, and initial clinical observations suggest that neither of them should be considered strains. Here we present consensus decisions on naming for both variants (West Africa: "Makona", Middle Africa: "Lomela") and provide database-compatible full, shortened, and abbreviated names that are in line with recently established filovirus sub-species nomenclatures.