15 research outputs found
Evaluation of Bluetongue Virus (BTV) Antibodies for the Immunohistochemical Detection of BTV and Other Orbiviruses
No full textThe detection of bluetongue virus (BTV) antigens in formalin-fixed tissues has been challenging; therefore, only a limited number of studies on suitable immunohistochemical approaches have been reported. This study details the successful application of antibodies for the immunohistochemical detection of BTV in BSR variant baby hamster kidney cells (BHK-BSR) and infected sheep lungs that were formalin-fixed and paraffin-embedded (FFPE). BTV reactive antibodies raised against non-structural (NS) proteins 1, 2, and 3/3a and viral structural protein 7 (VP7) were first evaluated on FFPE BTV-infected cell pellets for their ability to detect BTV serotype 1 (BTV-1). Antibodies that were successful in immunolabelling BTV-1 infected cell pellets were further tested, using similar methods, to determine their broader immunoreactivity against a diverse range of BTV and other orbiviruses. Antibodies specific for NS1, NS2, and NS3/3a were able to detect all BTV isolates tested, and the VP7 antibody cross-reacted with all BTV isolates, except BTV-15. The NS1 antibodies were BTV serogroup-specific, while the NS2, NS3/3a, and VP7 antibodies demonstrated immunologic cross-reactivity to related orbiviruses. These antibodies also detected viral antigens in BTV-3 infected sheep lung. This study demonstrates the utility of FFPE-infected cell pellets for the development and validation of BTV immunohistochemistry
Colocalization of hedgehog arterivirus 1 (HhAV-1) and histologic lesions in the European hedgehog (Erinaceus europaeus) with neurological disease
No full textThe European hedgehog (Erinaceus europaeus) is a protected species of conservation concern in the UK. In recent years, there have been multiple incidents of fatal encephalitis in captive hedgehogs in wildlife rescue centers associated with the molecular detection of a hedgehog arterivirus (HhAV-1). However, it remains unclear whether the virus is the causative agent of the central nervous system (CNS) lesions. In a retrospective investigation using postmortem material from 7 captive hedgehogs with neurological disease, and a single hedgehog with previously identified meningoencephalitis, histologic examination was conducted in tandem with viral RNA in situ hybridization (ISH) to appraise tissue distribution of HhAV-1 and the colocalization with histologic lesions. ISH revealed multicellular tropism of HhAV-1 involving monocyte-macrophage and vascular endothelial cells, with viral RNA detected in multiple organs, likely due to endotheliotropism and viremia. In the CNS, encephalomyelitis was mild whilst viral RNA was abundant and widely distributed, particularly in the microglial population and localized to areas with glial nodules. Splenic lymphoid depletion was generally mild but was moderate to severe in 2 septicemic animals. Brain samples from 13 control hedgehogs, found dead in the wild due to predation/trauma, were also screened for HhAV-1, of which 8 tested positive by real-time reverse transcription polymerase chain reaction (RT-PCR) with a low viral load. No CNS lesions or ISH labeling was observed in 2 of these control hedgehogs that could be examined histologically. Combined, these findings indicate that HhAV-1 infections in captive hedgehogs in English wildlife rescue centers may be associated with histopathologic alterations and clinical neurological disease
Colocalization of hedgehog arterivirus 1 (HhAV-1) and histologic lesions in the European hedgehog (Erinaceus europaeus) with neurological disease
No full textThe European hedgehog (Erinaceus europaeus) is a protected species of conservation concern in the UK. In recent years, there have been multiple incidents of fatal encephalitis in captive hedgehogs in wildlife rescue centers associated with the molecular detection of a hedgehog arterivirus (HhAV-1). However, it remains unclear whether the virus is the causative agent of the central nervous system (CNS) lesions. In a retrospective investigation using postmortem material from 7 captive hedgehogs with neurological disease, and a single hedgehog with previously identified meningoencephalitis, histologic examination was conducted in tandem with viral RNA in situ hybridization (ISH) to appraise tissue distribution of HhAV-1 and the colocalization with histologic lesions. ISH revealed multicellular tropism of HhAV-1 involving monocyte-macrophage and vascular endothelial cells, with viral RNA detected in multiple organs, likely due to endotheliotropism and viremia. In the CNS, encephalomyelitis was mild whilst viral RNA was abundant and widely distributed, particularly in the microglial population and localized to areas with glial nodules. Splenic lymphoid depletion was generally mild but was moderate to severe in 2 septicemic animals. Brain samples from 13 control hedgehogs, found dead in the wild due to predation/trauma, were also screened for HhAV-1, of which 8 tested positive by real-time reverse transcription polymerase chain reaction (RT-PCR) with a low viral load. No CNS lesions or ISH labeling was observed in 2 of these control hedgehogs that could be examined histologically. Combined, these findings indicate that HhAV-1 infections in captive hedgehogs in English wildlife rescue centers may be associated with histopathologic alterations and clinical neurological disease
Highly pathogenic avian influenza virus H5N1 infection in skua and gulls in the United Kingdom, 2022
No full textThe reemergence of the highly pathogenic avian influenza virus (HPAIV) subtype H5N1 in the United Kingdom in 2021-2022 has caused unprecedented epizootic events in wild birds and poultry. During the summer of 2022, there was a shift in virus transmission dynamics resulting in increased HPAIV infection in seabirds, and consequently, a profound impact on seabird populations. To understand the pathological impact of HPAIV in seabirds, we evaluated the virus antigen distribution and associated pathological changes in the tissues of great skua (Stercorarius skua, n = 8), long-tailed skua (Stercorarius longicaudus, n = 1), European herring gull (Larus argentatus, n = 5), and black-headed gull (Chroicocephalus ridibundus, n = 4), which succumbed to natural infection of HPAIV during the summer of 2022. Cases were collected from Shetland, including Scatness (mainland), No Ness (mainland), Clumlie (mainland), Hermaness (island), Fair Isle (island), Noss (island), and the West Midlands, South East, and South West of England. Grossly, gizzard ulceration was observed in one great skua and pancreatic necrosis was observed in 4 herring gulls, with intralesional viral antigen detected subsequently. Microscopical analysis revealed neuro-, pneumo-, lymphoid-, and cardiomyotropism of HPAIV H5N1, with the most common virus-associated pathological changes being pancreatic and splenic necrosis. Examination of the reproductive tract of the great skua revealed HPAIV-associated oophoritis and salpingitis, and virus replication within the oviductal epithelium. The emergence of HPAIV in seabirds Stercorariidae and Laridae, particularly during summer 2022, has challenged the dogma of HPAIV dynamics, posing a significant threat to wild bird life with potential implications for the reproductive performance of seabirds of conservation importance
SARS-CoV-2 infection and transmission via the skin to oro-nasal route with the production of bioaerosols in the ferret model.
No full textDirect and indirect transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been attributed to virus survival in droplets, bioaerosols and on fomites including skin and surfaces. Survival of SARS-CoV-2 variants of concern (Alpha, Beta, Gamma, and Delta) on the skin and virus transference following rounds of skin-to-skin contact were assessed on porcine skin as a surrogate for human skin. SARS-CoV-2 variants were detectable on skin by RT-qPCR after 72 h at biologically relevant temperatures (35.2 °C) with viral RNA (vRNA) detected after ten successive skin-to-skin contacts. Skin-to-skin virus transmission to establish infection in ferrets as a model for mild/asymptomatic SARS-CoV-2 infection in mustelids and humans was also investigated and compared to intranasal ferret inoculation. Naïve ferrets exposed to Delta variant SARS-CoV-2 in a 'wet' or 'dry' form on porcine skin resulted in robust infection with shedding detectable for up to 14 days post-exposure, at comparable viral loads to ferrets inoculated intranasally. Transmission of SARS-CoV-2 to naïve ferrets in direct contact with infected ferrets was achieved, with environmental contamination detected from ferret fur swabs and air samples. Genetic substitutions were identified in bioaerosol samples acquired following single contact passage in ferrets, including Spike, ORF1ab, and ORF3a protein sequences, suggesting a utility for monitoring host adaptation and virus evolution via air sampling. The longevity of SARS-CoV-2 variants survival directly on the skin and skin-to-skin transference, enabling subsequent infection via the skin to oro-nasal contact route, could represent a pathway for SARS-CoV-2 infection with implications to public and veterinary health
Development of immunohistochemistry and in situ hybridisation for the detection of SARS-CoV and SARS-CoV-2 in formalin-fixed paraffin-embedded specimens
No full textDetection of SARS-CoV-2 Delta Variant (B.1.617.2) in Domestic Dogs and Zoo Tigers in England and Jersey during 2021.
No full textReverse zoonotic transmission events of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been described since the start of the pandemic, and the World Organisation for Animal Health (WOAH) designated the detection of SARS-CoV-2 in animals a reportable disease. Eighteen domestic and zoo animals in Great Britain and Jersey were tested by APHA for SARS-CoV-2 during 2020-2023. One domestic cat (Felis catus), three domestic dogs (Canis lupus familiaris), and three Amur tigers (Panthera tigris altaica) from a zoo were confirmed positive during 2020-2021 and reported to the WOAH. All seven positive animals were linked with known SARS-CoV-2 positive human contacts. Characterisation of the SARS-CoV-2 variants by genome sequencing indicated that the cat was infected with an early SARS-CoV-2 lineage. The three dogs and three tigers were infected with the SARS-CoV-2 Delta variant of concern (B.1.617.2). The role of non-human species in the onward transmission and emergence of new variants of SARS-CoV-2 remain poorly defined. Continued surveillance of SARS-CoV-2 in relevant domestic and captive animal species with high levels of human contact is important to monitor transmission at the human-animal interface and to assess their role as potential animal reservoirs
Detection of Usutu virus infection in wild birds in the United Kingdom, 2020
No full textIn August 2020, as part of a long-term disease surveillance programme, Usutu virus was detected in five Eurasian blackbirds (Turdus merula) and one house sparrow (Passer domesticus) from Greater London, England. This was initially detected by reverse transcription- PCR and was confirmed by virus isolation and by immunohistochemical detection of flavivirus in tissues. Phylogenetic analysis identified Usutu virus African 3.2 lineage, which is prevalent in the Netherlands and Belgium, suggesting a potential incursion from mainland Europe
Detection of Usutu virus infection in wild birds in the United Kingdom, 2020
No full textIn August 2020, as part of a long-term disease surveillance programme, Usutu virus was detected in five Eurasian blackbirds (Turdus merula) and one house sparrow (Passer domesticus) from Greater London, England. This was initially detected by reverse transcription-PCR and was confirmed by virus isolation and by immunohistochemical detection of flavivirus in tissues. Phylogenetic analysis identified Usutu virus African 3.2 lineage, which is prevalent in the Netherlands and Belgium, suggesting a potential incursion from mainland Europe
Attenuation of Bluetongue Virus (BTV) in an <i>in ovo</i> Model Is Related to the Changes of Viral Genetic Diversity of Cell-Culture Passaged BTV
No full textThe embryonated chicken egg (ECE) is routinely used for the laboratory isolation and adaptation of Bluetongue virus (BTV) in vitro. However, its utility as an alternate animal model has not been fully explored. In this paper, we evaluated the pathogenesis of BTV in ovo using a pathogenic isolate of South African BTV serotype 3 (BTV-3) derived from the blood of an infected sheep. Endothelio- and neurotropism of BTV-3 were observed by immunohistochemistry of non-structural protein 1 (NS1), NS3, NS3/3a, and viral protein 7 (VP7) antigens. In comparing the pathogenicity of BTV from infectious sheep blood with cell-culture-passaged BTV, including virus propagated through a Culicoides-derived cell line (KC) or ECE, we found virus attenuation in ECE following cell-culture passage. Genomic analysis of the consensus sequences of segments (Seg)-2, -5, -6, -7, -8, -9, and -10 identified several nucleotide and amino-acid mutations among the cell-culture-propagated BTV-3. Deep sequencing analysis revealed changes in BTV-3 genetic diversity in various genome segments, notably a reduction of Seg-7 diversity following passage in cell culture. Using this novel approach to investigate BTV pathogenicity in ovo, our findings support the notion that pathogenic BTV becomes attenuated in cell culture and that this change is associated with virus quasispecies evolution
