scholarly journals The C962R ORF of African Swine Fever Strain Georgia Is Non-Essential and Not Required for Virulence in Swine

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 676 ◽  
Author(s):  
Elizabeth. Ramirez-Medina ◽  
Elizabeth. A. Vuono ◽  
Ayushi. Rai ◽  
Sarah. Pruitt ◽  
Ediane. Silva ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
Field Isolate ◽  
Protein A ◽  
African Swine Fever ◽  
Virus Genome ◽  
Economic Losses ◽  
Virus Protein ◽  
Swine Industry ◽  
Reading Frame

African swine fever virus (ASFV) is the causative agent of the African swine fever (ASF) epizootic currently affecting pigs throughout Eurasia, causing significant economic losses in the swine industry. The virus genome encodes for more than 160 genes, of which only a few have been studied in detail. Here we describe the previously uncharacterized ASFV open reading frame (ORF) C962R, a gene encoding for a putative NTPase. RNA transcription studies using infected swine macrophages demonstrate that the C962R gene is translated as a late virus protein. A recombinant ASFV lacking the C962R gene (ASFV-G-ΔC962R) demonstrates in vivo that the C962R gene is non-essential, since ASFV-G-ΔC962R has similar replication kinetics in primary swine macrophage cell cultures when compared to parental highly virulent field isolate Georgia2007 (ASFV-G). Experimental infection of domestic pigs with ASFV-G-ΔC962R produced a clinical disease similar to that caused by the parental ASFV-G, confirming that deletion of the C962R gene from the ASFV genome does not impact virulence.

scholarly journals Development and In Vivo Evaluation of a MGF110-1L Deletion Mutant in African Swine Fever Strain Georgia

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 286
Author(s):  
Elizabeth Ramirez-Medina ◽  
Elizabeth Vuono ◽  
Sarah Pruitt ◽  
Ayushi Rai ◽  
Ediane Silva ◽  
...  
Keyword(s):  
Deletion Mutant ◽  
African Swine Fever Virus ◽  
Field Isolate ◽  
African Swine Fever ◽  
Economic Losses ◽  
Swine Industry ◽  
In Vivo Evaluation ◽  
Viral Virulence

African swine fever (ASF) is currently causing an epizootic, affecting pigs throughout Eurasia, and causing significant economic losses in the swine industry. ASF is caused by African swine fever virus (ASFV) that consists of a large dsDNA genome that encodes for more than 160 genes; few of these genes have been studied in detail. ASFV contains four multi-gene family (MGF) groups of genes that have been implicated in regulating the immune response and host specificity; however, the individual roles of most of these genes have not been well studied. Here, we describe the evaluation of the previously uncharacterized ASFV MGF110-1L open reading frame (ORF) using a deletion mutant of the ASFV currently circulating throughout Eurasia. The recombinant ASFV lacking the MGF110-1L gene (ASFV-G-ΔMGF110-1L) demonstrated in vitro that the MGF110-1L gene is non-essential, since ASFV-G-ΔMGF110-1L had similar replication kinetics in primary swine macrophage cell cultures when compared to parental highly virulent field isolate Georgia2007 (ASFV-G). Experimental infection of domestic pigs with ASFV-G-ΔMGF110-1L produced a clinical disease similar to that caused by the parental ASFV-G, confirming that deletion of the MGF110-1L gene from the ASFV genome does not affect viral virulence.

Characterization of the African swine fever virus protein p49: a new late structural polypeptide

Microbiology ◽  
2000 ◽  
Vol 81 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Inmaculada Galindo ◽  
Eladio Viñuela ◽  
Angel L. Carrascosa
Keyword(s):  
Cell Attachment ◽  
African Swine Fever Virus ◽  
Rabbit Antiserum ◽  
African Swine Fever ◽  
Virus Genome ◽  
Fever Virus ◽  
Virus Protein ◽  
Significant Similarity ◽  
Reading Frame ◽  
Cell Extracts

The open reading frame B438L, located within the EcoRI B fragment of the African swine fever virus genome, is predicted to encode a protein of 438 amino acids with a molecular mass of 49·3 kDa. It presents a cell attachment RGD (Arg–Gly–Asp) motif but no other significant similarity to protein sequences in databases. Northern blot and primer extension analysis showed that B438L is transcribed only at late times during virus infection. The B438L gene product has been expressed in Escherichia coli, purified and used as an antigen for antibody production. The rabbit antiserum specific for pB438L recognized a protein of about 49 kDa in virus-infected cell extracts. This protein was synthesized late in infection by all the virus strains tested, was located in cytoplasmic virus factories and appeared as a structural component of purified virus particles.

scholarly journals The MGF360-16R ORF of African Swine Fever Virus Strain Georgia Encodes for a Nonessential Gene That Interacts with Host Proteins SERTAD3 and SDCBP

Viruses ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 60 ◽  
Author(s):  
Elizabeth Ramírez-Medina ◽  
Elizabeth A. Vuono ◽  
Lauro Velazquez-Salinas ◽  
Ediane Silva ◽  
Ayushi Rai ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
Field Isolate ◽  
African Swine Fever ◽  
Fever Virus ◽  
Host Protein ◽  
Parental Virus ◽  
Virus Protein ◽  
Host Proteins ◽  
Swine Industry ◽  
Nonessential Gene

African swine fever virus (ASFV) causes a contagious and frequently lethal disease of pigs with significant economic consequences to the swine industry. The ASFV genome encodes for more than 160 genes, but only a few of them have been studied in detail. Here we report the characterization of open reading frame (ORF) MGF360-16R. Kinetic studies of virus RNA transcription demonstrated that the MGF360-16R gene is transcribed as a late virus protein. Analysis of host–protein interactions for the MGF360-16R gene using a yeast two-hybrid screen identified SERTA domain containing 3 (SERTAD3) and syndecan-binding protein (SDCBP) as host protein binding partners. SERTAD3 and SDCBP are both involved in nuclear transcription and SDCBP has been shown to be involved in virus traffic inside the host cell. Interaction between MGF360-16R and SERTAD3 and SDCBP host proteins was confirmed in eukaryotic cells transfected with plasmids expressing MGF360-16R and SERTAD3 or SDCBP fused to fluorescent tags. A recombinant ASFV lacking the MGF360-16R gene (ASFV-G-ΔMGF360-16R) was developed from the highly virulent field isolate Georgia2007 (ASFV-G) and was used to show that MGF360-16R is a nonessential gene. ASFV-G-ΔMGF360-16R had a similar replication ability in primary swine macrophage cell cultures when compared to its parental virus ASFV-G. Experimental infection of domestic pigs showed that ASFV-G-ΔMGF360-16R is as virulent as the parental virus ASFV-G.

scholarly journals Computational Analysis of African Swine Fever Virus Protein Space for the Design of an Epitope-Based Vaccine Ensemble

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1078 ◽  
Author(s):  
Albert Ros-Lucas ◽  
Florencia Correa-Fiz ◽  
Laia Bosch-Camós ◽  
Fernando Rodriguez ◽  
Julio Alonso-Padilla
Keyword(s):  
T Cell ◽  
Vaccine Development ◽  
De Novo ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Virus Protein ◽  
Hemorrhagic Disease ◽  
Starting Point

African swine fever virus is the etiological agent of African swine fever, a transmissible severe hemorrhagic disease that affects pigs, causing massive economic losses. There is neither a treatment nor a vaccine available, and the only method to control its spread is by extensive culling of pigs. So far, classical vaccine development approaches have not yielded sufficiently good results in terms of concomitant safety and efficacy. Nowadays, thanks to advances in genomic and proteomic techniques, a reverse vaccinology strategy can be explored to design alternative vaccine formulations. In this study, ASFV protein sequences were analyzed using an in-house pipeline based on publicly available immunoinformatic tools to identify epitopes of interest for a prospective vaccine ensemble. These included experimentally validated sequences from the Immune Epitope Database, as well as de novo predicted sequences. Experimentally validated and predicted epitopes were prioritized following a series of criteria that included evolutionary conservation, presence in the virulent and currently circulating variant Georgia 2007/1, and lack of identity to either the pig proteome or putative proteins from pig gut microbiota. Following this strategy, 29 B-cell, 14 CD4+ T-cell and 6 CD8+ T-cell epitopes were selected, which represent a starting point to investigating the protective capacity of ASFV epitope-based vaccines.

scholarly journals BA71ΔCD2: a New Recombinant Live Attenuated African Swine Fever Virus with Cross-Protective Capabilities

2017 ◽  
Vol 91 (21) ◽  
Author(s):  
Paula L. Monteagudo ◽  
Anna Lacasta ◽  
Elisabeth López ◽  
Laia Bosch ◽  
Javier Collado ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Sub Saharan Africa ◽  
Swine Industry ◽  
Lethal Challenge ◽  
Major Threat ◽  
Attenuated Viruses ◽  
Genotype Ii

ABSTRACT African swine fever is a highly contagious viral disease of mandatory declaration to the World Organization for Animal Health (OIE). The lack of available vaccines makes its control difficult; thus, African swine fever virus (ASFV) represents a major threat to the swine industry. Inactivated vaccines do not confer solid protection against ASFV. Conversely, live attenuated viruses (LAV), either naturally isolated or obtained by genetic manipulation, have demonstrated reliable protection against homologous ASFV strains, although little or no protection has been demonstrated against heterologous viruses. Safety concerns are a major issue for the use of ASFV attenuated vaccine candidates and have hampered their implementation in the field so far. While trying to develop safer and efficient ASFV vaccines, we found that the deletion of the viral CD2v (EP402R) gene highly attenuated the virulent BA71 strain in vivo. Inoculation of pigs with the deletion mutant virus BA71ΔCD2 conferred protection not only against lethal challenge with the parental BA71 but also against the heterologous E75 (both genotype I strains). The protection induced was dose dependent, and the cross-protection observed in vivo correlated with the ability of BA71ΔCD2 to induce specific CD8+ T cells capable of recognizing both BA71 and E75 viruses in vitro. Interestingly, 100% of the pigs immunized with BA71ΔCD2 also survived lethal challenge with Georgia 2007/1, the genotype II strain of ASFV currently circulating in continental Europe. These results open new avenues to design ASFV cross-protective vaccines, essential to fight ASFV in areas where the virus is endemic and where multiple viruses are circulating. IMPORTANCE African swine fever virus (ASFV) remains enzootic in most countries of Sub-Saharan Africa, today representing a major threat for the development of their swine industry. The uncontrolled presence of ASFV has favored its periodic exportation to other countries, the last event being in Georgia in 2007. Since then, ASFV has spread toward neighboring countries, reaching the European Union's east border in 2014. The lack of available vaccines against ASFV makes its control difficult; so far, only live attenuated viruses have demonstrated solid protection against homologous experimental challenges, but they have failed at inducing solid cross-protective immunity against heterologous viruses. Here we describe a new LAV candidate with unique cross-protective abilities: BA71ΔCD2. Inoculation of BA71ΔCD2 protected pigs not only against experimental challenge with BA71, the virulent parental strain, but also against heterologous viruses, including Georgia 2007/1, the genotype II strain of ASFV currently circulating in Eastern Europe.

scholarly journals Risk of African swine fever virus introduction into the United States through smuggling of pork in air passenger luggage

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Cristina Jurado ◽  
Lina Mur ◽  
María Sol Pérez Aguirreburualde ◽  
Estefanía Cadenas-Fernández ◽  
Beatriz Martínez-López ◽  
...  
Keyword(s):  
Western Europe ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
The United States ◽  
Economic Losses ◽  
Swine Industry ◽  
Virus Surveillance ◽  
Global Epidemiology ◽  
The Us ◽  
Mean Risk

Abstract African swine fever causes substantial economic losses in the swine industry in affected countries. Traditionally confined to Africa with only occasional incursions into other regions, ASF began spreading into Caucasian countries and Eastern Europe in 2007, followed by Western Europe and Asia in 2018. Such a dramatic change in the global epidemiology of ASF has resulted in concerns that the disease may continue to spread into disease-free regions such as the US. In this study, we estimated the risk of introduction of ASF virus into the US through smuggling of pork in air passenger luggage. Results suggest that the mean risk of ASFV introduction into the US via this route has increased by 183.33% from the risk estimated before the disease had spread into Western Europe or Asia. Most of the risk (67.68%) was associated with flights originating from China and Hong Kong, followed by the Russian Federation (26.92%). Five US airports accounted for >90% of the risk. Results here will help to inform decisions related to the design of ASF virus surveillance strategies in the US.

scholarly journals Genetic characterisation of African swine fever virus from 2017 outbreaks in Zambia: Identification of p72 genotype II variants in domestic pigs

2018 ◽  
Vol 85 (1) ◽  
Author(s):  
Edgar Simulundu ◽  
Yona Sinkala ◽  
Herman M. Chambaro ◽  
Andrew Chinyemba ◽  
Frank Banda ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Variable Region ◽  
Economic Losses ◽  
African Region ◽  
Swine Industry ◽  
African Countries ◽  
Central Variable Region ◽  
Close Relationship ◽  
Haemorrhagic Disease

African swine fever (ASF) is a contagious haemorrhagic disease associated with causing heavy economic losses to the swine industry in many African countries. In 2017, Zambia experienced ASF outbreaks in Mbala District (Northern province) and for the first time in Isoka and Chinsali districts (Muchinga province). Meanwhile, another outbreak was observed in Chipata District (Eastern province). Genetic analysis of part of the B646L gene, E183L gene, CP204L gene and the central variable region of the B602L gene of ASF virus (ASFV) associated with the outbreaks in Mbala and Chipata districts was conducted. The results revealed that the ASFV detected in Mbala District was highly similar to that of the Georgia 2007/1 isolate across all the genome regions analysed. In contrast, while showing close relationship with the Georgia 2007/1 virus in the B646L gene, the ASFV detected in Chipata District showed remarkable genetic variation in the rest of the genes analysed. These results suggest that the Georgia 2007/1-like virus could be more diverse than what was previously thought, underscoring the need of continued surveillance and monitoring of ASFVs within the south-eastern African region to better understand their epidemiology and the relationships between outbreaks and their possible origin.

scholarly journals A new method for sampling African swine fever virus genome and its inactivation in environmental samples

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aleksandra Kosowska ◽  
Jose A. Barasona ◽  
Sandra Barroso-Arévalo ◽  
Belén Rivera ◽  
Lucas Domínguez ◽  
...  
Keyword(s):  
Early Detection ◽  
Environmental Samples ◽  
Sampling Method ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Virus Genome ◽  
Economic Losses ◽  
Effective Vaccine ◽  
Speed Up ◽  
Important Basis

AbstractAfrican swine fever (ASF) is currently the most dangerous disease for the global pig industry, causing huge economic losses, due to the lack of effective vaccine or treatment. Only the early detection of ASF virus (ASFV) and proper biosecurity measures are effective to reduce the viral expansion. One of the most widely recognized risks as regards the introduction ASFV into a country is infected animals and contaminated livestock vehicles. In order to improve ASF surveillance, we have assessed the capacity for the detection and inactivation of ASFV genome by using Dry-Sponges (3 M) pre-hydrated with a new surfactant liquid. We sampled different surfaces in ASFV-contaminated facilities, including animal skins, and the results were compared to those obtained using a traditional sampling method. The surfactant liquid successfully inactivated the virus, while ASFV DNA was well preserved for the detection. This is an effective method to systematically recover ASFV DNA from different surfaces and skin, which has a key applied relevance in surveillance of vehicles transporting live animals and greatly improves animal welfare. This method provides an important basis for the detection of ASFV genome that can be assessed without the biosafety requirements of a BSL-3 laboratory at least in ASF-affected countries, which may substantially speed up the early detection of the pathogen.

scholarly journals Short and Long-read Sequencing Survey of the Dynamic Transcriptomes of African Swine Fever Virus and its Host

2020 ◽  
Author(s):  
Ferenc Olasz ◽  
Dóra Tombácz ◽  
Gábor Torma ◽  
Zsolt Csabai ◽  
Norbert Moldován ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Swine Industry ◽  
Rna Molecules ◽  
Oxford Nanopore ◽  
Combined Use ◽  
Long Read ◽  
Low Coverage

AbstractAfrican swine fever virus (ASFV) is an important animal pathogen causing substantial economic losses in the swine industry globally. At present, little is known about the molecular biology of ASFV, including its transcriptome organization. In this study, we applied cutting-edge sequencing approaches, namely the Illumina short-read sequencing (SRS) and the Oxford Nanopore Technologies long-read sequencing (LRS) techniques, together with several library preparation chemistries to analyze the ASFV dynamic transcriptome. SRS can generate a large amount of high-precision sequencing reads, but it is inefficient for identifying long RNA molecules, transcript isoforms and overlapping transcripts. LRS can overcome these limitations, but this approach also has shortcomings, such as its high error rate and the low coverage. Amplification-based LRS techniques produce relatively high read counts but also high levels of spurious transcripts, whereas the non-amplified cDNA and direct RNA sequencing techniques are more precise but achieve lower throughput. The drawbacks of the various technologies can be circumvented by the combined use of these approaches.

scholarly journals The Progressive Adaptation of a Georgian Isolate of African Swine Fever Virus to Vero Cells Leads to a Gradual Attenuation of Virulence in Swine Corresponding to Major Modifications of the Viral Genome

2014 ◽  
Vol 89 (4) ◽  
pp. 2324-2332 ◽  
Author(s):  
Peter W. Krug ◽  
Lauren G. Holinka ◽  
Vivian O'Donnell ◽  
Bo Reese ◽  
Brenton Sanford ◽  
...  
Keyword(s):  
Cell Lines ◽  
Protective Efficacy ◽  
African Swine Fever Virus ◽  
Field Isolate ◽  
African Swine Fever ◽  
Vero Cells ◽  
Fever Virus ◽  
Cultured Cell ◽  
Attenuated Viruses

ABSTRACTAfrican swine fever virus (ASFV) causes a contagious and often lethal disease of feral and domestic swine. Experimental vaccines derived from naturally occurring, genetically modified, or cell culture-adapted ASFV have been evaluated, but no commercial vaccine is available to control African swine fever (ASF). We report here the genotypic and phenotypic analysis of viruses obtained at different passages during the process of adaptation of a virulent ASFV field isolate from the Republic of Georgia (ASFV-G) to grow in cultured cell lines. ASFV-G was successively passaged 110 times in Vero cells. Viruses obtained at passages 30, 60, 80, and 110 were evaluatedin vitrofor the ability to replicate in Vero cells and primary swine macrophages cultures andin vivofor assessing virulence in swine. Replication of ASFV-G in Vero cells increased with successive passages, corresponding to a decreased replication in primary swine macrophages cultures.In vivo, progressive loss of virus virulence was observed with increased passages in Vero cells, and complete attenuation of ASFV-G was observed at passage 110. Infection of swine with the fully attenuated virus did not confer protection against challenge with virulent parental ASFV-G. Full-length sequence analysis of each of these viruses revealed significant deletions that gradually accumulated in specific areas at the right and left variable ends of the genome. Mutations that result in amino acid substitutions and frameshift mutations were also observed, though in a rather limited number of genes. The potential importance of these genetic changes in virus adaptation/attenuation is discussed.IMPORTANCEThe main problem in controlling ASF is the lack of vaccines. Attempts to produce vaccines by adaptation of ASFV to cultured cell lines have been made. These attempts led to the production of attenuated viruses that conferred only homologous protection. Specifics regarding adaptation of these isolates to cell cultures have been insufficiently described. Details like the numbers of passages required to obtain attenuated viruses, genetic modifications introduced into the virus genomes along passages, and the extent of attenuation and induced protective efficacy are not readily available. In this study, we assessed the changes that lead to decreased growth in swine macrophages and to attenuation in swine. Loss of virulence, probably associated with limited replicationin vivo, may lead to the lack of protective immunity in swine observed after challenge. This report provides valuable information that can be used to further the understanding of ASFV gene function, virus attenuation, and protection against infection.

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