315 research outputs found
Different Outcomes of Experimental Hepatitis E Virus Infection in Diverse Mouse Strains, Wistar Rats, and Rabbits
Hepatitis E virus (HEV) is the causative agent of acute hepatitis E in humans in developing countries, but autochthonous cases of zoonotic genotype 3 (HEV-3) infection also occur in industrialized countries. In contrast to swine, rats, and rabbits, natural HEV infections in mice have not yet been demonstrated. The pig represents a well-established large animal model for HEV-3 infection, but a suitable small animal model mimicking natural HEV-3 infection is currently missing. Therefore, we experimentally inoculated C57BL/6 mice (wild-type, IFNAR−/−, CD4−/−, CD8−/−) and BALB/c nude (nu/nu) mice, Wistar rats, and European rabbits with a wild boar-derived HEV-3 strain and monitored virus replication and shedding, as well as humoral immune responses. HEV RNA and anti-HEV antibodies were detected in one and two out of eight of the rats and all rabbits inoculated, respectively, but not in any of the mouse strains tested. Remarkably, immunosuppressive dexamethasone treatment of rats did not enhance their susceptibility to HEV infection. In rabbits, immunization with recombinant HEV-3 and ratHEV capsid proteins induced protection against HEV-3 challenge. In conclusion, the rabbit model for HEV-3 infection may serve as a suitable alternative to the non-human primate and swine models, and as an appropriate basis for vaccine evaluation studies
A Medicinal Herb Scutellaria lateriflora Inhibits PrP Replication in vitro and Delays the Onset of Prion Disease in Mice
Transmissible spongiform encephalopathies (TSE) are characterized by the misfolding of the host encoded prion protein (PrPC) into a pathogenic isoform (PrPSc) which leads to the accumulation of β-sheet-rich fibrils and subsequent loss of neurons and synaptic functions. Although many compounds have been identified which inhibit accumulation or dissolve fibrils and aggregates in vitro there is no therapeutic treatment to stop these progressive neurodegenerative diseases. Here we describe the effects of the traditional medicinal herb Scutellaria lateriflora (S. lateriflora) and its natural compounds, the flavonoids baicalein and baicalin, on the development of prion disease using in vitro and in vivo models. S. lateriflora extract as well as both constituents reduced the PrPres accumulation in scrapie-infected cell cultures and cell-free conversion assays and lead to the destabilization of pre-existing PrPSc fibrils. Moreover, tea prepared from S. lateriflora, prolonged significantly the incubation time of scrapie-infected mice upon oral treatment. Therefore S. lateriflora extracts as well as the individual compounds can be considered as promising candidates for the development of new therapeutic drugs against TSEs and other neurodegenerative diseases like Alzheimer’s and Parkinson’s disease
Rapid testing leads to the underestimation of the scrapie prevalence in an affected sheep and goat flock
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
Participatory survey of risk factors and pathways for Rift Valley fever in pastoral and agropastoral communities of Uganda
To assess pastoralists’ and agropastoralists’ knowledge on Rift Valley fever (RVF), participatory epidemiological studies were conducted with 215 livestock keepers and 27 key informants in Napak, Butebo, Isingiro and Lyantonde districts, Uganda, between January and February 2022. Livestock keepers in all four districts had knowledge of RVF and even had local names or descriptions for it. Pastoralists and agropastoralists possessed valuable knowledge of RVF clinical descriptions and epidemiological risk factors such as the presence of infected mosquitoes, living in flood-prone areas, and excessive rainfall. RVF was ranked among the top ten most important cattle diseases. Pastoralists called RVF Lonyang, symbolizing a disease associated with jaundice, high fever, abortions in pregnant cows, and sudden death in calves. Key informants identified infected domestic animals, the presence of infected mosquitoes, livestock movement and trade, and infected wild animals as risk pathways for the introduction of RVF into an area. Drinking raw blood and milk was perceived as the most likely pathway for human exposure to RVF virus; while the highest consequence was high treatment costs. The results indicate that pastoralists provided key epidemiological information that could be essential for designing an effective national RVF surveillance and early warning system
Sheep as the Hosts of the Crimean-Congo Hemorrhagic Fever Virus in Kosova
Crimean-Congo Hemorrhagic Fever (CCHF) virus which cause danger disease in country of Balkan. But also, this disease is none in Asia, Africa, and South Europe in Kosovo, Albania, Macedonia, Greece, Bulgaria, and Serbia. There strong evidence that the Kosovo sheep appear to play a role as virus and tick-vector host. We tested sheep from 5 municipality (Peja, Gjakova, Junik, Prishtina, Hani Elezit). It was tested 137 blood samples of sheep with the immunological ELISA method. Specific IgG antibody were detected in all sampled municipality, and detected high prevalence in municipality Gjakova 100% and Prishtina 83,33%, followed with Peja 25%, Hani Elezit 12 % and Junik 10%. In basis of result which we receive, we can conclude that the CCHFV is present and circulate in sheep of Kosovo municipality in border of Albania, Serbia, Montenegro and Macedonia
Sheep as the Hosts of the Crimean-Congo Hemorrhagic Fever Virus in Kosova
Crimean-Congo Hemorrhagic Fever (CCHF) virus which cause danger disease in country of Balkan. But also, this disease is none in Asia, Africa, and South Europe in Kosovo, Albania, Macedonia, Greece, Bulgaria, and Serbia. There strong evidence that the Kosovo sheep appear to play a role as virus and tick-vector host. We tested sheep from 5 municipality (Peja, Gjakova, Junik, Prishtina, Hani Elezit). It was tested 137 blood samples of sheep with the immunological ELISA method. Specific IgG antibody were detected in all sampled municipality, and detected high prevalence in municipality Gjakova 100% and Prishtina 83,33%, followed with Peja 25%, Hani Elezit 12 % and Junik 10%. In basis of result which we receive, we can conclude that the CCHFV is present and circulate in sheep of Kosovo municipality in border of Albania, Serbia, Montenegro and Macedonia. Keywords: Virus, CCHF, Sheep, ELISA, Kosovo
West Nile virus antibody prevalence in horses of Ukraine
West Nile virus (WNV) is a mosquito-borne virus of global importance. Over the
last two decades, it has been responsible for significant numbers of cases of
illness in humans and animals in many parts of the world. In Ukraine, WNV
infections in humans and birds were first reported more than 25 years ago, yet
the current epidemiological status is quite unclear. In this study, serum
samples from over 300 equines were collected and screened in order to detect
current WNV activity in Ukraine with the goal to estimate the risk of
infection for humans and horses. Sera were tested by enzyme-linked
immunosorbent assay (ELISA) and virus neutralization assay (NT) to detect WNV-
specific antibodies. The results clearly revealed that WNV circulates in most
of the regions from which samples were obtained, shown by a WNV seroprevalence
rate of 13.5% of examined horses. This is the first topical report indicating
the presence of WNV infections in horses in Ukraine, and the results of this
study provide evidence of a widespread WNV circulation in this country
BSE infectivity in jejunum, ileum and ileocaecal junction of incubating cattle
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
Evidence for West Nile Virus and Usutu Virus Infections in Wild and Resident Birds in Germany, 2017 and 2018
Wild birds play an important role as reservoir hosts and vectors for zoonotic arboviruses and foster their spread. Usutu virus (USUV) has been circulating endemically in Germany since 2011, while West Nile virus (WNV) was first diagnosed in several bird species and horses in 2018. In 2017 and 2018, we screened 1709 live wild and zoo birds with real-time polymerase chain reaction and serological assays. Moreover, organ samples from bird carcasses submitted in 2017 were investigated. Overall, 57 blood samples of the live birds (2017 and 2018), and 100 organ samples of dead birds (2017) were positive for USUV-RNA, while no WNV-RNA-positive sample was found. Phylogenetic analysis revealed the first detection of USUV lineage Europe 2 in Germany and the spread of USUV lineages Europe 3 and Africa 3 towards Northern Germany. USUV antibody prevalence rates were high in Eastern Germany in both years. On the contrary, in Northern Germany, high seroprevalence rates were first detected in 2018, with the first emergence of USUV in this region. Interestingly, high WNV-specific neutralizing antibody titers were observed in resident and short-distance migratory birds in Eastern Germany in 2018, indicating the first signs of a local WNV circulation
Seroepidemiological Survey of West Nile Virus Infections in Horses from Berlin/Brandenburg and North Rhine-Westphalia, Germany
Following the introduction of the West Nile virus (WNV) into eastern Germany in 2018, increasing infections have been diagnosed in birds, equines, and humans over time, while the spread of WNV into western Germany remained unclear. We screened 437 equine sera from 2018 to 2020, excluding vaccinated horses, collected from convenience sampled patients in the eastern and western parts of Germany, for WNV-specific antibodies (ELISAs followed by virus/specific neutralization tests) and genomes (RT-qPCRs). Clinical presentations, final diagnoses, and demographic data were also recorded. In the eastern part, a total of eight horses were found WNV seropositive in 2019 (seroprevalence of 8.16%) and 27 in 2020 (13.77%). There were also two clinically unsuspected horses with WNV-specific antibodies in the western part from 2020 (2.63%), albeit travel history-related infections could not be excluded. None of the horse sera contained WNV-specific genomes. Eight horses in eastern Germany carried WNV-IgM antibodies, but only four of these showed typical clinical signs. These results underline the difficulty of detecting a WNV infection in a horse solely based on clinical signs. Thus, WNV circulation is established in the horse population in eastern Germany, but not yet in the western part
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