180 research outputs found

    Rapid testing leads to the underestimation of the scrapie prevalence in an affected sheep and goat flock

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    To obtain a more detailed understanding of the prevalence of classical scrapie infections in a heavily affected German sheep flock (composed of 603 sheep and 6 goats), we analysed 169 sheep and 6 goats that carried the genotypes susceptible to the disease and that were therefore culled following discovery of the index case. The initial tests were performed using the Biorad TeSeE ELISA and reactive results were verified by official confirmatory methods (OIE-immunoblot and/or immunohistochemistry (IHC)) to demonstrate the deposition of scrapie-associated PrPSc in the brain stem (obex). This approach led to the discovery of 40 additional subclinically scrapie-infected sheep. Furthermore, peripheral lymphatic and nervous tissue samples of the 129 sheep and 6 goats with a negative CNS result were examined by IHC in order to identify any preclinical infections which had not already spread to the central nervous system (CNS). Using this approach we found 13 additional sheep with PrPSc depositions in the gut-associated lymph nodes (GALT) as well as in the enteric nervous system. Moreover, in most of these cases PrPSc was also deposited in the spleen and in the retropharyngeal and superficial cervical lymph nodes. Taken together, these results show a 30.3% infection prevalence in this scrapie-affected flock. Almost 7.4% of the infected animals harboured PrPSc exclusively in the peripheral lymphatic and nervous tissue and were therefore missed by the currently used testing strategy

    Identification of rhabdoviral sequences in oropharyngeal swabs from German and Danish bats

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    BACKGROUND: In the frame of active lyssavirus surveillance in bats, oropharyngeal swabs from German (N = 2297) and Danish (N = 134) insectivorous bats were investigated using a newly developed generic pan-lyssavirus real-time reverse transcriptase PCR (RT-qPCR). FINDINGS: In total, 15 RT-qPCR positive swabs were detected. Remarkably, sequencing of positive samples did not confirm the presence of bat associated lyssaviruses but revealed nine distinct novel rhabdovirus-related sequences. CONCLUSIONS: Several novel rhabdovirus-related sequences were detected both in German and Danish insectivorous bats. The results also prove that the novel generic pan-lyssavirus RT-qPCR offers a very broad detection range that allows the collection of further valuable data concerning the broad and complex diversity within the family Rhabdoviridae

    Prion Infectivity and PrPBSE in the Peripheral and Central Nervous System of Cattle 8 Months Post Oral BSE Challenge

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    After oral exposure of cattle with classical bovine spongiform encephalopathy (C-BSE), the infectious agent ascends from the gut to the central nervous system (CNS) primarily via the autonomic nervous system. However, the timeline of this progression has thus far remained widely undetermined. Previous studies were focused on later time points after oral exposure of animals that were already 4 to 6 months old when challenged. In contrast, in this present study, we have orally inoculated 4 to 6 weeks old unweaned calves with high doses of BSE to identify any possible BSE infectivity and/or PrPBSE in peripheral nervous tissues during the first eight months postinoculation (mpi). For the detection of BSE infectivity, we used a bovine PrP transgenic mouse bioassay, while PrPBSE depositions were analyzed by immunohistochemistry (IHC) and by protein misfolding cyclic amplification (PMCA). We were able to show that as early as 8 mpi the thoracic spinal cord as well as the parasympathetic nodal ganglion of these animals contained PrPBSE and BSE infectivity. This shows that the centripetal prion spread starts early after challenge at least in this age group, which represents an essential piece of information for the risk assessments for food, feed, and pharmaceutical products produced from young calves

    BSE infectivity in jejunum, ileum and ileocaecal junction of incubating cattle

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    To establish bovine spongiform encephalopathy (BSE) public health protection measures it is important to precisely define the cattle tissues considered as specified risk materials (SRM). To date, in pre-clinical BSE infected cattle, no evidence of the BSE agent had been found in the gut outside of the ileal Peyer's Patches. This study was undertaken to determine when and where the pathological prion protein (PrPSc) and/or BSE infectivity can be found in the small intestine of cattle 4 to 6 months of age, orally challenged with BSE. Samples of the jejunum, the ileum and the ileocaecal junction from 46 BSE infected cattle, culled from 1 up to 44 months post infection (mpi) were examined by immunohistochemistry. Samples from cattle 8 mpi to 20 mpi were additionally studied by PTA Western blot, rapid tests, and by mouse (TgbovXV) bioassay. In doing so nearly all of the cattle, from 4 up to 44 mpi, had detectable amounts of PrPSc and/or infectivity in the distal ileum. In the distal ileum clear time-dependent variations were visible concerning the amount of PrPSc, the tissue structures affected, and the cells involved. BSE infectivity was found not only in the ileum and ileocaecal junction but also in the jejunum. The systematic approach of this study provides new data for qualitative and quantitative risk assessments and allows defining bovine SRM more precisely

    2022 taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales

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    In March 2022, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by two new families (bunyaviral Discoviridae and Tulasviridae), 41 new genera, and 98 new species. Three hundred forty-nine species were renamed and/or moved. The accidentally misspelled names of seven species were corrected. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.Instituto de Patología VegetalFil: Kuhn, Jens H. National Institute of Allergy and Infectious Diseases. National Institutes of Health. Integrated Research Facility at Fort Detrick; Estados UnidosFil: Adkins, Scott. US Horticultural Research Laboratory. United States Department of Agriculture. Agricultural Research Service; Estados UnidosFil: Alkhovsky, Sergey V. Ministry of Health of Russian Federation. National Center on Epidemiology and Microbiology .D.I. Ivanovsky Institute of Virology of N.F. Gamaleya; RusiaFil: Avšič-Županc, Tatjana. University of Ljubljana. Faculty of Medicine. Institute of Microbiology and Immunology; EsloveniaFil: Ayllón, María A. Universidad Politécnica de Madrid. Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria.Centro de Biotecnología y Genómica de Plantas; EspañaFil: Ayllón, María A. Universidad Politécnica de Madrid. Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas. Departamento de Biotecnología-Biología Vegetal; EspañaFil: Bahl, Justin. University of Georgia. Center for Ecology of Infectious Diseases. Insitute of Bioinformatics. Department of Infectious Diseases. Department of Epidemiology and Biostatistics; Estados UnidosFil: Balkema-Buschmann, Anne. Friedrich-Loeffler-Institut. Institute of Novel and Emerging Infectious Diseases; AlemaniaFil: Ballinger, Matthew J. Mississippi State University. Department of Biological Sciences; Estados UnidosFil: Bandte, Martina. Humboldt-Universität zu Berlin. Faculty of Life Sciences. Division Phytomedicine; AlemaniaFil: Beer, Martin. Friedrich-Loeffler-Institut. Institute of Diagnostic Virology; AlemaniaFil: Bejerman, Nicolas Esteban. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Bejerman, Nicolas Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Lodden Økland, Arnfnn. Pharmaq Analytiq; Norueg
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