scholarly journals A Simple Method for Sample Preparation to Facilitate Efficient Whole-Genome Sequencing of African Swine Fever Virus

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1129 ◽  
Author(s):  
Ferenc Olasz ◽  
István Mészáros ◽  
Szilvia Marton ◽  
Győző L. Kaján ◽  
Vivien Tamás ◽  
...  

In the recent years, African swine fever has become the biggest animal health threat to the swine industry. To facilitate quick genetic analysis of its causative agent, the African swine fever virus (ASFV), we developed a simple and efficient method for next generation sequencing of the viral DNA. Execution of the protocol does not demand complicated virus purification steps, enrichment of the virus by ultracentrifugation or of the viral DNA by ASFV-specific PCRs, and minimizes the use of Sanger sequencing. Efficient DNA-se treatment, monitoring of sample preparation by qPCR, and whole genome amplification are the key elements of the method. Through detailed description of sequencing of the first Hungarian ASFV isolate (ASFV_HU_2018), we specify the sensitive steps and supply key reference numbers to assist reproducibility and to facilitate the successful use of the method for other ASFV researchers.

2021 ◽  
Vol 8 (12) ◽  
pp. 290
Author(s):  
Andrei Ungur ◽  
Cristina Daniela Cazan ◽  
Luciana Cătălina Panait ◽  
Marian Taulescu ◽  
Oana Maria Balmoș ◽  
...  

The World Organisation for Animal Health has listed African swine fever as the most important deadly disease in domestic swine around the world. The virus was recently brought from South-East Africa to Georgia in 2007, and it has since expanded to Russia, Eastern Europe, China, and Southeast Asia, having a devastating impact on the global swine industry and economy. In this study, we report for the first time the molecular characterization of nine African swine fever virus (ASFV) isolates obtained from domestic pigs in Mureş County, Romania. All nine Romanian samples clustered within p72 genotype II and showed 100% identity with all compared isolates from Georgia, Armenia, Russia, Azerbaijan, Ukraine, Belarus, Lithuania, and Poland. This is the first report of ASFV genotype II in the country.


Virology ◽  
1989 ◽  
Vol 173 (1) ◽  
pp. 251-257 ◽  
Author(s):  
Rafael Blasco ◽  
Inmaculada de la Vega ◽  
Fernando Almazan ◽  
Montserrat Aguero ◽  
Eladio Viñuela

2017 ◽  
Vol 91 (21) ◽  
Author(s):  
Paula L. Monteagudo ◽  
Anna Lacasta ◽  
Elisabeth López ◽  
Laia Bosch ◽  
Javier Collado ◽  
...  

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.


2017 ◽  
Vol 145 (13) ◽  
pp. 2787-2796 ◽  
Author(s):  
J. P. NIELSEN ◽  
T. S. LARSEN ◽  
T. HALASA ◽  
L. E. CHRISTIANSEN

SUMMARYThe spread of African swine fever virus (ASFV) threatens to reach further parts of Europe. In countries with a large swine production, an outbreak of ASF may result in devastating economic consequences for the swine industry. Simulation models can assist decision makers setting up contingency plans. This creates a need for estimation of parameters. This study presents a new analysis of a previously published study. A full likelihood framework is presented including the impact of model assumptions on the estimated transmission parameters. As animals were only tested every other day, an interpretation was introduced to cover the weighted infectiousness on unobserved days for the individual animals (WIU). Based on our model and the set of assumptions, the within- and between-pen transmission parameters were estimated to βw = 1·05 (95% CI 0·62–1·72), βb = 0·46 (95% CI 0·17–1·00), respectively, and the WIU = 1·00 (95% CI 0–1). Furthermore, we simulated the spread of ASFV within a pig house using a modified SEIR-model to establish the time from infection of one animal until ASFV is detected in the herd. Based on a chosen detection limit of 2·55% equivalent to 10 dead pigs out of 360, the disease would be detected 13–19 days after introduction.


2019 ◽  
Vol 25 (6) ◽  
pp. 1249-1252 ◽  
Author(s):  
Jan H. Forth ◽  
Marylène Tignon ◽  
Ann Brigitte Cay ◽  
Leonie F. Forth ◽  
Dirk Höper ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254815
Author(s):  
Jinyu Fu ◽  
Yueping Zhang ◽  
Guang Cai ◽  
Geng Meng ◽  
Shuobo Shi

African swine fever (ASF) is a serious contagious disease that causes fatal haemorrhagic fever in domestic and wild pigs, with high morbidity. It has caused devastating damage to the swine industry worldwide, necessitating the focus of attention on detection of the ASF pathogen, the African swine fever virus (ASFV). In order to overcome the disadvantages of conventional diagnostic methods (e.g. time-consuming, demanding and unintuitive), quick detection tools with higher sensitivity need to be explored. In this study, based on the conserved p72 gene sequence of ASFV, we combined the Cas12a-based assay with recombinase polymerase amplification (RPA) and a fluorophore-quencher (FQ)-labeled reporter assay for rapid and visible detection. Five crRNAs designed for Cas12a-based assay showed specificity with remarkable fluorescence intensity under visual inspection. Within 20 minutes, with an initial concentration of two copies of DNA, the assay can produce significant differences between experimental and negative groups, indicating the high sensitivity and rapidity of the method. Overall, the developed RPA-Cas12a-fluorescence assay provides a fast and visible tool for point-of-care ASFV detection with high sensitivity and specificity, which can be rapidly performed on-site under isothermal conditions, promising better control and prevention of ASF.


2018 ◽  
Vol 6 ◽  
pp. 863-869
Author(s):  
Stelian Baraitareanu ◽  
Dragos Cobzariu ◽  
Mihaela Popp ◽  
Marius Valer Campeanu ◽  
Doina Danes

INTRODUCTION: In 2007, African swine fever virus (ASFv) broken its well-known boundaries. This was the reference year for the first report of African swine fever (ASF) in Georgia. Subsequently, the virus reached pigs and boars in Armenia and Russia. From the Caucasus area, ASFv jumped in all directions, between the Black Sea and the Caspian Sea, in relation to the density of backyard pigs and their trade. In the next ten years there have been notifications and registrations of ASFv outbreaks in Russia, Azerbaijan, Ukraine, Belarus, Lithuania, Poland, Estonia, Latvia, Moldova and the Czech Republic. Romania faced the first ASFv outbreak at the end of July 2017, in backyard pigs." in stead "density of backyard pigs and their trade. In the next ten years there have been notifications and registrations of ASFv outbreaks in Russia, Azerbaijan, Ukraine, Belarus, Lithuania, Poland, Estonia, Latvia, Moldova and the Czech Republic. Romania faced the first ASFv outbreak at the end of July 2017, in backyard pigs.OBJECTIVES: The aim of study is to analyse the ways ASFv spread from and into different regions recorded by Eastern European states.METHODS: The immediate notifications on ASFv to the World Organisation for Animal Health (OIE) were analysed from the Eastern-European states between 2007 and 2017. The analysis took into consideration the first occurrence of the disease under scrutiny in the country and the follow-up reports, in relation with the geospatial distribution of the outbreaks.RESULTS: The main route of ASFv introduction into local pig populations indicated by the Member States of the European Union was the trans-boundary circulation of boars. However, the spread of ASFv through both, wild and domestic pigs and also by the human alimentary customs/traditions in the affected areas shouldn’t be ignored. Three cycles of ASFv transmission have been identified and described by the epidemiologists: the domestic cycle, the sylvatic cycle and the tick-pig cycle.CONCLUSION: None of the ways to disseminate the ASFv should be excluded, and the origin of the first outbreaks remains unknown or inconclusive in Eastern EU states.


2022 ◽  
Vol 8 ◽  
Author(s):  
Kexin Zhong ◽  
Mengmeng Zhu ◽  
Qichao Yuan ◽  
Zhibang Deng ◽  
Simeng Feng ◽  
...  

African swine fever (ASF) is a highly detrimental viral disease caused by African swine fever virus (ASFV). The occurrence and prevalence of this disease have become a serious threat to the global swine industry and national economies. At present, the detection volume of African swine fever is huge, more sensitive and accurate detection techniques are needed for the market. pp62 protein, as a protein in the late stage of infection, has strong antigenicity and a high corresponding antibody titer in infected pigs. In this study, the CP530R gene was cloned into expression vector pET-28a to construct a prokaryotic expression plasmid, which was induced by IPTG to express soluble pp62 protein. Western blot analysis showed that it had great reactivity. Using the purified recombinant protein as an antigen, an indirect ELISA method for detecting ASFV antibody was established. The method was specific only to ASFV-positive serum, 1:1600 diluted positive serum could still be detected, and the coefficients of variation (CV) of the intra assay and inter assay were both <10%. It turns out that the assays had excellent specificity, sensitivity, and repeatability. This provides an accurate, rapid, and economical method for the detection of ASFV antibody in clinical pig serum samples.


2021 ◽  
Vol 12 ◽  
Author(s):  
Elena Riera ◽  
Daniel Pérez-Núñez ◽  
Raquel García-Belmonte ◽  
Lisa Miorin ◽  
Adolfo García-Sastre ◽  
...  

African swine fever virus (ASFV) causes a serious disease in domestic pigs and wild boars and is currently expanding worldwide. No safe and efficacious vaccines against ASFV are available, which threats the swine industry worldwide. African swine fever virus (ASFV) is a complex dsDNA virus that displays multiple mechanisms to counteract the host innate immune response, whose efficacy might determine the different degrees of virulence displayed by attenuated and virulent ASFV strains. Here we report that infection with both virulent Arm/07/CBM/c2 and attenuated NH/P68 strains prevents interferon-stimulated gene (ISG) expression in interferon (IFN)-treated cells by counteracting the JAK/STAT pathway. This inhibition results in an impaired nuclear translocation of the interferon-stimulated gene factor 3 (ISGF3) complex, as well as in the proteasome-dependent STAT2 degradation and caspase 3-dependent STAT1 cleavage. The existence of two independent mechanisms of control of the JAK/STAT pathway, suggests the importance of preventing this pathway for successful viral replication. As ASFV virulence is likely associated with the efficacy of the IFN signaling inhibitory mechanisms, a better understanding of these IFN antagonistic properties may lead to new strategies to control this devastating pig disease.


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