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2.
Viruses ; 13(11)2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34834943

RESUMO

Infectious agents including viruses are important abortifacients and can cause fetal abnormalities in livestock animals. Here, samples that had been collected in Israel from aborted or malformed ruminant fetuses between 2015 and 2019 were investigated for the presence of the following viruses: the reoviruses bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV), the flaviviruses bovine viral diarrhea virus (BVDV) and border disease virus (BDV), the peribunyaviruses Shuni virus (SHUV) and Akabane virus (AKAV), bovine herpesvirus type 1 (BoHV-1) and bovine ephemeral fever virus (BEFV). Domestic (cattle, sheep, goat) and wild/zoo ruminants were included in the study. The presence of viral nucleic acid or antigen could be confirmed in 21.8 % of abnormal pregnancies (213 out of 976 investigated cases), with peribunyaviruses, reoviruses and pestiviruses being the most prevalent. At least four different BTV serotypes were involved in abnormal courses of pregnancy in Israel. The subtyping of pestiviruses revealed the presence of two BDV and several distinct BVDV type 1 strains. The peribunyaviruses AKAV and SHUV were identified annually throughout the study period, however, variation in the extent of virus circulation could be observed between the years. In 2018, AKAV even represented the most detected pathogen in cases of small domestic ruminant gestation abnormalities. In conclusion, it was shown that various viruses are involved in abnormal courses of pregnancy in ruminants in Israel.

3.
Infect Ecol Epidemiol ; 11(1): 1992083, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34777715

RESUMO

Wild aquatic birds are the main natural host reservoir of avian influenza viruses (AIV). Migratory aquatic birds can translocate AI viruses over wide geographic distances. AIV may be transmitted reciprocally at the wild bird-poultry interface, increasing viral variability and potentially driving the zoonotic potential of these viruses. A cross-sectional study on AIV and several further avian viral pathogens conducted in 396 trapped migratory aquatic birds traded at live bird markets (LBM) in northern Iran identified 11 AIV-positive cases. The 10 identified H9N2 viral sequences fell into wild bird H9 lineage Y439; in addition, an H10N3 virus of Eurasian lineage was detected. Ten samples contained low viral loads of avian coronavirus but could not be further characterized. Although traditional trading of live-trapped wild birds provides income for hunters, particularly during fall migration periods, it increases the risk of introducing new AIV strains from the natural reservoir to poultry kept at LBMs and, potentially, to traders and customers. Banning these birds from poultry trading lines would lower such risks considerably.

4.
Biologicals ; 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34736782

RESUMO

The Zoonoses Anticipation and Preparedness Initiative (ZAPI) was set up to prepare for future outbreaks and to develop and implement new technologies to accelerate development and manufacturing of vaccines and monoclonal antibodies. To be able to achieve surge capacity, an easy deployment and production at multiple sites is needed. This requires a straightforward manufacturing system with a limited number of steps in upstream and downstream processes, a minimum number of in vitro Quality Control assays, and robust and consistent platforms. Three viruses were selected as prototypes: Middle East Respiratory Syndrome (MERS) coronavirus, Rift Valley fever virus, and Schmallenberg virus. Selected antibodies against the viral surface antigens were manufactured by transient gene expression in Chinese Hamster Ovary (CHO) cells, scaling up to 200 L. For vaccine production, viral antigens were fused to multimeric protein scaffold particles using the SpyCatcher/SpyTag system. In vivo models demonstrated the efficacy of both antibodies and vaccines. The final step in speeding up vaccine (and antibody) development is the regulatory appraisal of new platform technologies. Towards this end, within ZAPI, a Platform Master File (PfMF) was developed, as part of a licensing dossier, to facilitate and accelerate the scientific assessment by avoiding repeated discussion of already accepted platforms. The veterinary PfMF was accepted, whereas the human PfMF is currently under review by the European Medicines Agency, aiming for publication of the guideline by January 2022.

5.
Virus Evol ; 7(2): veab085, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34703624

RESUMO

Proactive approaches in preventing future epidemics include pathogen discovery prior to their emergence in human and/or animal populations. Playing an important role in pathogen discovery, high-throughput sequencing (HTS) enables the characterization of microbial and viral genetic diversity within a given sample. In particular, metagenomic HTS allows the unbiased taxonomic profiling of sequences; hence, it can identify novel and highly divergent pathogens such as viruses. Newly discovered viral sequences must be further investigated using genomic characterization, molecular and serological screening, and/or in vitro and in vivo characterization. Several outbreak and surveillance studies apply unbiased generic HTS to characterize the whole genome sequences of suspected pathogens. In contrast, this study aimed to screen for novel and unexpected pathogens in previously generated HTS datasets and use this information as a starting point for the establishment of an early warning system (EWS). As a proof of concept, the EWS was applied to HTS datasets and archived samples from the 2018-9 West Nile virus (WNV) epidemic in Germany. A metagenomics read classifier detected sequences related to genome sequences of various members of Riboviria. We focused the further EWS investigation on viruses belonging to the families Peribunyaviridae and Reoviridae, under suspicion of causing co-infections in WNV-infected birds. Phylogenetic analyses revealed that the reovirus genome sequences clustered with sequences assigned to the species Umatilla virus (UMAV), whereas a new peribunyavirid, tentatively named 'Hedwig virus' (HEDV), belonged to a putative novel genus of the family Peribunyaviridae. In follow-up studies, newly developed molecular diagnostic assays detected fourteen UMAV-positive wild birds from different German cities and eight HEDV-positive captive birds from two zoological gardens. UMAV was successfully cultivated in mosquito C6/36 cells inoculated with a blackbird liver. In conclusion, this study demonstrates the power of the applied EWS for the discovery and characterization of unexpected viruses in repurposed sequence datasets, followed by virus screening and cultivation using archived sample material. The EWS enhances the strategies for pathogen recognition before causing sporadic cases and massive outbreaks and proves to be a reliable tool for modern outbreak preparedness.

6.
Viruses ; 13(9)2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34578300

RESUMO

The introduction of genotype II African swine fever (ASF) virus, presumably from Africa into Georgia in 2007, and its continuous spread through Europe and Asia as a panzootic disease of suids, continues to have a huge socio-economic impact. ASF is characterized by hemorrhagic fever leading to a high case/fatality ratio in pigs. In Europe, wild boar are especially affected. This review summarizes the currently available knowledge on ASF in wild boar in Europe. The current ASF panzootic is characterized by self-sustaining cycles of infection in the wild boar population. Spill-over and spill-back events occur from wild boar to domestic pigs and vice versa. The social structure of wild boar populations and the spatial behavior of the animals, a variety of ASF virus (ASFV) transmission mechanisms and persistence in the environment complicate the modeling of the disease. Control measures focus on the detection and removal of wild boar carcasses, in which ASFV can remain infectious for months. Further measures include the reduction in wild boar density and the limitation of wild boar movements through fences. Using these measures, the Czech Republic and Belgium succeeded in eliminating ASF in their territories, while the disease spread in others. So far, no vaccine is available to protect wild boar or domestic pigs reliably against ASF.

7.
Viruses ; 13(9)2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34578322

RESUMO

In this article, we describe the development and evaluation of a double antigen sandwich enzyme-linked immunosorbent assay (ELISA) able to detect serotype 4-specific antibodies from BTV-4 infected or vaccinated animals using a recombinant BTV-4 VP2 protein. The coding sequence of VP2 was inserted into a pVote plasmid by recombination in the Gateway® cloning system. Vaccinia virus (VacV) was used as a vector for the expression of the recombinant VP2. After production in BSR cells, recombinant VP2 was purified by immunoprecipitation using a FLAG tag and then used both as the coated ELISA antigen and as the HRP-tagged conjugate. The performance of the ELISA was evaluated with 1186 samples collected from BTV negative, infected or vaccinated animals. The specificity and sensitivity of the BTV-4 ELISA were above the expected standards for the detection of anti-BTV-4 VP2 antibodies in animals reared in Europe or in the Mediterranean basin. Cross-reactions were observed with reference sera for serotypes 10 and 20, and to a lesser extent with serotypes 12, 17 and 24, due to their genetic proximity to serotype 4. Nevertheless, these serotypes have never been detected in Europe and the Mediterranean area. This ELISA, which requires only the production of a recombinant protein, can be used to detect BTV serotype 4-specific antibodies and is therefore an attractive alternative diagnostic method to serum neutralization.

8.
Animals (Basel) ; 11(9)2021 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-34573568

RESUMO

African swine fever (ASF) is one of the most important and devastating viral diseases in wild boar and domestic pigs worldwide. In the absence of vaccines or treatment options, early clinical detection is crucial and requires a sound knowledge of disease characteristics. To provide practitioners and state veterinarians with detailed information, the objective of the present study was to characterize the ASF virus (ASFV) isolate "Belgium 2018/1" in subadult and weaning domestic pigs. To this end, two animal trials were performed. Trial A included eight subadult domestic pigs and trial B five weaner pigs. In general, clinical signs and pathological lesions were in line with previous studies utilizing highly virulent ASF genotype II viruses. However, in trial A, four subadult domestic pigs survived and recovered, pointing to an age-dependent outcome. The long-term fate of these survivors remains under discussion and would need further investigation.

9.
Res Vet Sci ; 140: 229-232, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34534904

RESUMO

Several non-variant of concern SARS-CoV-2 infections in pets have been reported as documented in the OIE and GISAID databases and there is only one fully documented case of an alpha variant of concern (VOC)(B.1.1.7) in the United States so far. Here, we describe the first case in a cat infected with the alpha SARS-CoV-2 variant in Germany. A cat suffering from pneumonia was presented to a veterinary practice. The pneumonia was treated symptomatically, but 16 days later the cat was presented again. Since the owner had been tested positive for a SARS-CoV-2 infection in the meantime, swab samples were taken from the cat and analyzed for SARS-CoV-2 specific nucleic acids. The various RT-qPCR analyses and whole-genome sequencing revealed the presence of the SARS-CoV-2 B.1.1.7 variant in this cat. This study shows that pets living in close contact with SARS-CoV-2 B.1.1.7 infected owners can contract this virus and also suffer from a respiratory disease. It is not clear yet whether onward transmissions to other cats and humans can occur. To minimize transmission risks, pet owners and veterinarians should comply to the hygienic rules published by OIE and others. It must be stated, that infections of cats with SARS-CoV-2 is still a rare event. Cats with clinical signs of a respiratory disease should be presented to a veterinarian, who will decide on further steps.


Assuntos
COVID-19 , Doenças do Gato , Animais , COVID-19/veterinária , Doenças do Gato/diagnóstico , Gatos , Alemanha , Humanos , Reação em Cadeia da Polimerase em Tempo Real/veterinária , SARS-CoV-2
10.
Blood ; 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34587242

RESUMO

SARS-CoV-2 vaccine ChAdOx1 nCov-19 (AstraZeneca) causes a thromboembolic complication termed vaccine-induced immune thrombotic thrombocytopenia (VITT). Using biophysical techniques, mouse models and analysis of VITT patient samples we identified determinants of this vaccine-induced adverse reaction. Super-resolution microscopy visualized vaccine components forming antigenic complexes with platelet factor 4 (PF4) on platelet surfaces to which anti-PF4 antibodies obtained from VITT patients bound. PF4/vaccine complex formation was charge-driven and increased by addition of DNA. Proteomics identified substantial amounts of virus production-derived T-REx HEK293 proteins in the EDTA-containing vaccine. Injected vaccine increased vascular leakage in mice leading to systemic dissemination of vaccine components known to stimulate immune responses. Together, PF4/vaccine complex formation and the vaccine-stimulated proinflammatory milieu trigger a pronounced B cell response that results in the formation of high-avidity anti-PF4 antibodies in VITT patients. The resulting high-titer anti-PF4 antibodies potently activated platelets in the presence of PF4 or DNA and polyphosphate polyanions. Anti-PF4 VITT patient antibodies also stimulated neutrophils to release NETs in a platelet PF4-dependent manner. Biomarkers of procoagulant NETs were elevated in VITT patient serum, and NETs were visualized in abundance by immunohistochemistry in cerebral vein thrombi obtained from VITT patients. Together, vaccine-induced PF4/adenovirus aggregates and proinflammatory reactions stimulate pathologic anti-PF4 antibody production that drive thrombosis in VITT. The data support a two-step mechanism underlying VITT that resembles the pathogenesis of (autoimmune) heparin-induced thrombocytopenia.

11.
Diagn Microbiol Infect Dis ; 101(4): 115520, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34536911

RESUMO

Sample panels of SARS-CoV-2 cases were retrospectively whole-genome sequenced. In three individuals, samples of upper and lower respiratory tract resulted in identical sequences suggesting virus stability including the spike protein cleavage site. In a fourth case, low-level intra-host genomic evolution and a unique 5-nucleotide deletion was observed.


Assuntos
Adaptação Fisiológica/genética , COVID-19/virologia , Sistema Respiratório/virologia , SARS-CoV-2/isolamento & purificação , Sequenciamento Completo do Genoma , Genoma Viral , Humanos , Estudos Retrospectivos , Distribuição Tecidual
12.
BMC Infect Dis ; 21(1): 787, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376142

RESUMO

BACKGROUND: The true burden and geographical distribution of human Borna disease virus 1 (BoDV-1) encephalitis is unknown. All detected cases so far have been recorded in Bavaria, southern Germany. CASE PRESENTATION: A retrospective laboratory and epidemiological investigation of a 2017 case of fatal encephalitis in a farmer in Brandenburg, northeast Germany, demonstrated BoDV-1 as causative agent by polymerase chain reaction, immunohistochemistry and in situ hybridization. Next-generation sequencing showed that the virus belonged to a cluster not known to be endemic in Brandenburg. The investigation was triggered by a recent outbreak of animal Borna disease in the region. Multiple possible exposures were identified. The next-of-kin were seronegative. CONCLUSIONS: The investigation highlights clinical awareness for human BoDV-1 encephalitis which should be extended to all areas endemic for animal Borna disease. All previously diagnosed human cases had occurred > 350 km further south. Further testing of shrews and livestock with Borna disease may show whether this BoDV-1 cluster is additionally endemic in the northwest of Brandenburg.


Assuntos
Doença de Borna , Vírus da Doença de Borna , Encefalite , Animais , Doença de Borna/epidemiologia , Vírus da Doença de Borna/genética , Alemanha/epidemiologia , Humanos , Estudos Retrospectivos
13.
Viruses ; 13(8)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34452496

RESUMO

Due to changing distemper issues worldwide and to inadequate results of an inter-laboratory study in Germany, it seems sensible to adapt and optimize the diagnostic methods for the detection of the canine distemper virus (CDV) to the new genetic diversity of virus strains. The goal of the project was the development, establishment and validation of two independent one-step reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) methods for the safe detection of CDV in domestic and wild animals. For this purpose, an existing CDV-RT-qPCR was decisively adapted and, in addition, a completely new system was developed. Both CDV-RT-qPCR systems are characterized by a very high, comparable analytical and diagnostic sensitivity and specificity and can be mutually combined with inhibition or extraction controls. The reduction in the master mix used allows for the parallel implementation of both CDV-RT-qPCR systems without significant cost increases. For validation of the new CDV-RT-qPCR duplex assays, a panel comprising 378 samples derived from Germany, several European countries and one African country were tested. A sensitivity of 98.9% and a specificity of 100% were computed for the new assays, thus being a reliable molecular diagnostic tool for the detection of CDV in domestic and wild animals.

14.
Adv Virus Res ; 110: 59-102, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34353482

RESUMO

Within only one year after the first detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), nearly 100 million infections were reported in the human population globally, with more than two million fatal cases. While SARS-CoV-2 most likely originated from a natural wildlife reservoir, neither the immediate viral precursor nor the reservoir or intermediate hosts have been identified conclusively. Due to its zoonotic origin, SARS-CoV-2 may also be relevant to animals. Thus, to evaluate the host range of the virus and to assess the risk to act as potential animal reservoir, a large number of different animal species were experimentally infected with SARS-CoV-2 or monitored in the field in the last months. In this review, we provide an update on studies describing permissive and resistant animal species. Using a scoring system based on viral genome detection subsequent to SARS-CoV-2 inoculation, seroconversion, the development of clinical signs and transmission to conspecifics or humans, the susceptibility of diverse animal species was classified on a semi-quantitative scale. While major livestock species such as pigs, cattle and poultry are mostly resistant, companion animals appear moderately susceptible, while several model animal species used in research, including several Cricetidae species and non-human primates, are highly susceptible to SARS-CoV-2 infection. By natural infections, it became obvious that American minks (Neovison vison) in fur farms, e.g., in the Netherlands and Denmark are highly susceptible resulting in local epidemics in these animals.


Assuntos
COVID-19/veterinária , SARS-CoV-2/fisiologia , Animais , Animais Selvagens/virologia , COVID-19/diagnóstico , COVID-19/transmissão , COVID-19/virologia , Reservatórios de Doenças/veterinária , Reservatórios de Doenças/virologia , Suscetibilidade a Doenças/diagnóstico , Suscetibilidade a Doenças/veterinária , Suscetibilidade a Doenças/virologia , Especificidade de Hospedeiro , Gado/virologia , Modelos Animais , Animais de Estimação/virologia , SARS-CoV-2/isolamento & purificação
15.
Viruses ; 13(8)2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34452513

RESUMO

The recent emergence of SARS-CoV-2 in humans from a yet unidentified animal reservoir and the capacity of the virus to naturally infect pets, farmed animals and potentially wild animals has highlighted the need for serological surveillance tools. In this study, the luciferase immunoprecipitation systems (LIPS), employing the spike (S) and nucleocapsid proteins (N) of SARS-CoV-2, was used to examine the suitability of the assay for antibody detection in different animal species. Sera from SARS-CoV-2 naturally-infected mink (n = 77), SARS-CoV-2 experimentally-infected ferrets, fruit bats and hamsters and a rabbit vaccinated with a purified spike protein were examined for antibodies using the SARS-CoV-2 N and/or S proteins. From comparison with the known neutralization status of the serum samples, statistical analyses including calculation of the Spearman rank-order-correlation coefficient and Cohen's kappa agreement were used to interpret the antibody results and diagnostic performance. The LIPS immunoassay robustly detected the presence of viral antibodies in naturally infected SARS-CoV-2 mink, experimentally infected ferrets, fruit bats and hamsters as well as in an immunized rabbit. For the SARS-CoV-2-LIPS-S assay, there was a good level of discrimination between the positive and negative samples for each of the five species tested with 100% agreement with the virus neutralization results. In contrast, the SARS-CoV-2-LIPS-N assay did not consistently differentiate between SARS-CoV-2 positive and negative sera. This study demonstrates the suitability of the SARS-CoV-2-LIPS-S assay for the sero-surveillance of SARS-CoV-2 infection in a range of animal species.


Assuntos
Anticorpos Antivirais/sangue , COVID-19/veterinária , Vison/imunologia , SARS-CoV-2/imunologia , Animais , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/imunologia , Teste Sorológico para COVID-19 , Quirópteros/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Monitoramento Epidemiológico , Furões/imunologia , Imunoprecipitação , Mesocricetus/imunologia , Fosfoproteínas/imunologia , Coelhos/imunologia , Estudos Soroepidemiológicos , Glicoproteína da Espícula de Coronavírus/imunologia
16.
Arch Virol ; 166(12): 3513-3566, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34463877

RESUMO

In March 2021, 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 four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and Gammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

17.
Viruses ; 13(7)2021 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203238

RESUMO

The development of new diagnostic methods resulted in the discovery of novel hepaciviruses in wild populations of the bank vole (Myodes glareolus, syn. Clethrionomys glareolus). The naturally infected voles demonstrate signs of hepatitis similar to those induced by hepatitis C virus (HCV) in humans. The aim of the present research was to investigate the geographical distribution of bank vole-associated hepaciviruses (BvHVs) and their genetic diversity in Europe. Real-time reverse transcription polymerase chain reaction (RT-qPCR) screening revealed BvHV RNA in 442 out of 1838 (24.0%) bank voles from nine European countries and in one of seven northern red-backed voles (Myodes rutilus, syn. Clethrionomys rutilus). BvHV RNA was not found in any other small mammal species (n = 23) tested here. Phylogenetic and isolation-by-distance analyses confirmed the occurrence of both BvHV species (Hepacivirus F and Hepacivirus J) and their sympatric occurrence at several trapping sites in two countries. The broad geographical distribution of BvHVs across Europe was associated with their presence in bank voles of different evolutionary lineages. The extensive geographical distribution and high levels of genetic diversity of BvHVs, as well as the high population fluctuations of bank voles and occasional commensalism in some parts of Europe warrant future studies on the zoonotic potential of BvHVs.

18.
PLoS One ; 16(7): e0254872, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34280238

RESUMO

BACKGROUND: COVID-19 is only partly understood, and the level of evidence available in terms of pathophysiology, epidemiology, therapy, and long-term outcome remains limited. During the early phase of the pandemic, it was necessary to effectively investigate all aspects of this new disease. Autopsy can be a valuable procedure to investigate the internal organs with special techniques to obtain information on the disease, especially the distribution and type of organ involvement. METHODS: During the first wave of COVID-19 in Germany, autopsies of 19 deceased patients were performed. Besides gross examination, the organs were analyzed with standard histology and polymerase-chain-reaction for SARS-CoV-2. Polymerase chain reaction positive localizations were further analyzed with immunohistochemistry and RNA-in situ hybridization for SARS-CoV-2. RESULTS: Eighteen of 19 patients were found to have died due to COVID-19. Clinically relevant histological changes were only observed in the lungs. Diffuse alveolar damage in considerably different degrees was noted in 18 cases. Other organs, including the central nervous system, did not show specific micromorphological alterations. In terms of SARS-CoV-2 detection, the focus remains on the upper airways and lungs. This is true for both the number of positive samples and the viral load. A highly significant inverse correlation between the stage of diffuse alveolar damage and viral load was found on a case and a sample basis. Mediastinal lymph nodes and fat were also affected by the virus at high frequencies. By contrast, other organs rarely exhibited a viral infection. Moderate to strong correlations between the methods for detecting SARS-CoV-2 were observed for the lungs and for other organs. CONCLUSIONS: The lung is the most affected organ in gross examination, histology and polymerase chain reaction. SARS-CoV-2 detection in other organs did not reveal relevant or specific histological changes. Moreover, we did not find CNS involvement.


Assuntos
COVID-19/virologia , Sistema Nervoso Central/virologia , Pulmão/virologia , Linfonodos/virologia , Carga Viral , Idoso , Idoso de 80 Anos ou mais , Autopsia/estatística & dados numéricos , COVID-19/epidemiologia , COVID-19/patologia , Sistema Nervoso Central/patologia , Feminino , Humanos , Pulmão/patologia , Linfonodos/patologia , Masculino , Pessoa de Meia-Idade
19.
Transbound Emerg Dis ; 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34312995

RESUMO

African swine fever (ASF) is one of the most important viral diseases of domestic pigs and wild boar. Apart from endemic cycles in Africa, ASF is now continuously spreading in Europe and Asia. As ASF leads to severe but unspecific clinical signs and high lethality, early pathogen detection is of utmost importance. Recently, 'point-of-care' (POC) tests, especially immunochromatographic assays, have been intensively discussed for the use in remote areas but also in the context of on-farm epidemiological investigations and wild boar carcass screening. The later topic was the starting point for our present study. In detail, we evaluated the performance of the commercially available INGEZIM ASFV CROM Ag lateral flow assay (Eurofins Technologies Ingenasa) with selected high-quality reference blood samples, and with blood samples from wild boar carcasses collected under field conditions in Germany. While we observed a sensitivity of roughly 77% in freeze-thawed matrices of close to ideal quality, our approach to simulate field conditions in direct testing of blood samples from carcasses without any modification, resulted in a drastically reduced sensitivity of only 12.5% with the given sample set. Freeze thawing increased the sensitivity to roughly 44% which mirrored the overall sensitivity of 49% in the total data set of wild boar carcass samples. A diagnostic specificity of 100% was observed. In summary, the antigen LFA should not be regarded as a substitute for any OIE listed diagnostic method and has very limited use for carcass testing at the point of care. For optimized LFA antigen tests, the sensitivity with field samples must be significantly increased. An improved sensitivity is seen with freeze-thawed samples, which may indicate problems in the accessibility of ASFV antigen that could be overcome, to a certain extent, with assay modifications.

20.
Vaccines (Basel) ; 9(6)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203630

RESUMO

Emerging infectious diseases represent an increasing threat to human and animal health. Therefore, safe and effective vaccines that could be available within a short time frame after an outbreak are required for adequate prevention and control. Here, we developed a robust and versatile self-assembling multimeric protein scaffold particle (MPSP) vaccine platform using lumazine synthase (LS) from Aquifex aeolicus. This scaffold allowed the presentation of peptide epitopes by genetic fusion as well as the presentation of large antigens by bacterial superglue-based conjugation to the pre-assembled particle. Using the orthobunyavirus model Schmallenberg virus (SBV) we designed MPSPs presenting major immunogens of SBV and assessed their efficacy in a mouse model as well as in cattle, a target species of SBV. All prototype vaccines conferred protection from viral challenge infection and the multivalent presentation of the selected antigens on the MPSP markedly improved their immunogenicity compared to the monomeric subunits. Even a single shot vaccination protected about 80% of mice from an otherwise lethal dose of SBV. Most importantly, the MPSPs induced a virtually sterile immunity in cattle. Altogether, LS represents a promising platform for modular and rapid vaccine design.

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