Re‐emergence of genotype I of African swine fever virus in Ivory Coast

2018 ◽  
Vol 66 (2) ◽  
pp. 882-896 ◽  
Author(s):  
Emmanuel Couacy‐Hymann ◽  
Kouamé V. Kouakou ◽  
Jenna E. Achenbach ◽  
Léonce Kouadio ◽  
Yao M. Koffi ◽  
...  
Keyword(s):  
Ivory Coast ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Genotype I

scholarly journals Differential vector competence of Ornithodoros soft ticks for African swine fever virus: What if it involves more than just crossing organic barriers in ticks?

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Rémi Pereira De Oliveira ◽  
Evelyne Hutet ◽  
Renaud Lancelot ◽  
Frédéric Paboeuf ◽  
Maxime Duhayon ◽  
...  
Keyword(s):  
Viral Replication ◽  
Vertical Transmission ◽  
African Swine Fever Virus ◽  
Vector Competence ◽  
African Swine Fever ◽  
Realistic Model ◽  
Molecular Data ◽  
Fever Virus ◽  
Genotype I ◽  
Genotype Ii

Abstract Background Several species of soft ticks in genus Ornithodoros are known vectors and reservoirs of African swine fever virus (ASFV). However, the underlying mechanisms of vector competence for ASFV across Ornithodoros species remain to be fully understood. To that end, this study compared ASFV replication and dissemination as well as virus vertical transmission to descendants between Ornithodorosmoubata, O. erraticus, and O. verrucosus in relation to what is known about the ability of these soft tick species to transmit ASFV to pigs. To mimic the natural situation, a more realistic model was used where soft ticks were exposed to ASFV by allowing them to engorge on viremic pigs. Methods Ornithodoros moubata ticks were infected with the ASFV strains Liv13/33 (genotype I) or Georgia2007/1 (genotype II), O. erraticus with OurT88/1 (genotype I) or Georgia2007/1 (genotype II), and O. verrucosus with Ukr12/Zapo (genotype II), resulting in five different tick–virus pairs. Quantitative PCR (qPCR) assays targeting the VP72 ASFV gene was carried out over several months on crushed ticks to study viral replication kinetics. Viral titration assays were also carried out on crushed ticks 2 months post infection to confirm virus survival in soft ticks. Ticks were dissected. and DNA was individually extracted from the following organs to study ASFV dissemination: intestine, salivary glands, and reproductive organs. DNA extracts from each organ were tested by qPCR. Lastly, larval or first nymph-stage progeny emerging from hatching eggs were tested by qPCR to assess ASFV vertical transmission. Results Comparative analyses revealed higher rates of ASFV replication and dissemination in O. moubata infected with Liv13/33, while the opposite was observed for O. erraticus infected with Georgia2007/1 and for O. verrucosus with Ukr12/Zapo. Intermediate profiles were found for O. moubata infected with Georgia2007/1 and for O. erraticus with OurT88/1. Vertical transmission occurred efficiently in O. moubata infected with Liv13/33, and at very low rates in O. erraticus infected with OurT88/1. Conclusions This study provides molecular data indicating that viral replication and dissemination in Ornithodoros ticks are major mechanisms underlying ASFV horizontal and vertical transmission. However, our results indicate that other determinants beyond viral replication also influence ASFV vector competence. Further research is required to fully understand this process in soft ticks.

scholarly journals Identification and Isolation of Two Different Subpopulations Within African Swine Fever Virus Arm/07 Stock

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 625
Author(s):  
Daniel Pérez-Núñez ◽  
Eva Castillo-Rosa ◽  
Gonzalo Vigara-Astillero ◽  
Raquel García-Belmonte ◽  
Carmina Gallardo ◽  
...  
Keyword(s):  
Vaccine Development ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Single Mutation ◽  
High Sequence Identity ◽  
Genotype I ◽  
High Coverage ◽  
Purification Method

No efficient vaccines exist against African swine fever virus (ASFV), which causes a serious disease in wild boars and domestic pigs that produces great industrial and ecological concerns worldwide. An extensive genetic characterization of the original ASFV stocks used to produce live attenuated vaccine (LAV) prototypes is needed for vaccine biosecurity and control. Here, we sequenced for the first time the Arm/07 stock which was obtained from an infected pig during the Armenia outbreak in 2007, using an improved viral dsDNA purification method together with high coverage analysis. There was unexpected viral heterogeneity within the stock, with two genetically distinct ASFV subpopulations. The first, represented by the Arm/07/CBM/c2 clone, displayed high sequence identity to the updated genotype II Georgia 2007/1, whereas the second (exemplified by clone Arm/07/CBM/c4) displayed a hemadsorbing phenotype and grouped within genotype I based on a central region conserved among all members of this group. Intriguingly, Arm/07/CBM/c4 contained a unique EP402R sequence, produced by a single mutation in the N-terminal region. Importantly, Arm/07/CBM/c4 showed in vitro features of attenuated strains regarding innate immune response pathway. Both Arm/07/CBM/c2 and c4 represent well-characterized viral clones, useful for different molecular and virus-host interaction studies, including virulence studies and vaccine development.

scholarly journals African Swine Fever in Cameroon: A Review

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 421
Author(s):  
Ebanja Joseph Ebwanga ◽  
Stephen Mbigha Ghogomu ◽  
Jan Paeshuyse
Keyword(s):  
African Swine Fever Virus ◽  
Central Africa ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Future Research ◽  
Genotype I ◽  
Traditional System ◽  
Pork Industry ◽  
Domestic Cycle

African swine fever (ASF) is a hemorrhagic contagious porcine disease caused by the African swine fever virus. The disease poses enormous problems to the pork industry with pig mortality ranging from 30% to 100%, depending on the virulence of the virus circulating. Cameroon, situated in Central Africa is one of the countries in which the African swine fever virus (ASFV) has been endemic since its first outbreak in 1982. The disease is a major problem to the pig industry causing huge economic losses. A clear and concise review on ASF in Cameroon relating to the entry and current genotype of the virus, epidemiology, pathogenesis and economic impact is lacking. A thorough literature search revealed: (1) The virus entered the country in 1982 and caused the death of 80% of the pigs. (2) All isolates belong to serogroup I and only Genotype I is circulating in Cameroon principally in the domestic cycle as there are neither soft ticks nor warthog in the pig production regions sampled. (3) 70% of the pig farmers are involved in the traditional system of production with local and hybrid breeds of pigs with minimal input. (4) The country is endemic to the virus with huge economic losses. (5) So far, very little research has been effected on ASFV in Cameroon. This review gives a detailed overview of the situation of African swine fever virus (ASFV) in the country along with potential avenues for future research into ASFV in Cameroon.

scholarly journals Role of African swine fever virus (ASFV) proteins EP153R and EP402R in reducing viral persistence in blood and virulence in pigs infected with BeninΔDP148R

2021 ◽  
Author(s):  
Vlad Petrovan ◽  
Anusyah Rathakrishnan ◽  
Muneeb Islam ◽  
Lynnette C. Goatley ◽  
Katy Moffat ◽  
...  
Keyword(s):  
Vaccine Development ◽  
African Swine Fever Virus ◽  
Clinical Signs ◽  
African Swine Fever ◽  
Fever Virus ◽  
Genotype I ◽  
Virus Persistence ◽  
Challenge Virus

The limited knowledge on the role of many of the approximately 170 proteins encoded by African swine fever virus restricts progress towards vaccine development. Previously, the DP148R gene was deleted from the genome of genotype I virulent Benin 97/1 isolate. This virus, BeninΔDP148R, induced transient moderate clinical signs after immunization and high levels of protection against challenge. However, the BeninΔDP148R virus and genome persisted in blood over a prolonged period. In the current study deletion of either EP402R or EP153R genes individually or in combination from BeninΔDP148R genome was shown not to reduce virus replication in macrophages in vitro. However, deletion of EP402R dramatically reduced the period of infectious virus persistence in blood in immunized pigs from 28 to 14 days and virus genome from 59 to 14 days, whilst maintaining high levels of protection against challenge. The additional deletion of EP153R (BeninΔDP148RΔEP153RΔEP402R) further attenuated the virus and no viremia or clinical signs were observed post-immunization. This was associated with decreased protection and detection of moderate levels of challenge virus in blood. Interestingly, the deletion of EP153R alone from BeninΔDP148R did not result in further virus attenuation and did not reduce the period of virus persistence in blood. These results show that EP402R and EP153R have a synergistic role in reducing clinical signs and levels of virus in blood. Importance: African swine fever virus (ASFV) causes a disease of domestic pigs and wild boar which results in death of almost all infected animals. The disease has a high economic impact, and no vaccine is available. We investigated the role of two ASFV proteins, called EP402R and EP153R, in determining the levels and length of time virus persists in blood from infected pigs. EP402R causes ASFV particles and infected cells to bind to red blood cells. Deletion of the EP402R gene dramatically reduced virus persistence in blood but did not reduce the level of virus. Deletion of the EP153R alone did not reduce the period or level of virus persistence in blood. However, deleting both EP153R and EP402R resulted in undetectable levels of virus in blood and no clinical signs showing the proteins act synergistically. Importantly the infected pigs were protected following infection with the wildtype virus that kills pigs.

scholarly journals First Genomic Evidence of Dual African Swine Fever Virus Infection: Case Report from Recent and Historical Outbreaks in Sardinia

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2145
Author(s):  
Mariangela Stefania Fiori ◽  
Luca Ferretti ◽  
Matteo Floris ◽  
Federica Loi ◽  
Antonello Di Nardo ◽  
...  
Keyword(s):  
Case Report ◽  
Virus Infection ◽  
Wild Boar ◽  
Phylogenetic Relationship ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Genotype I ◽  
Genome Wide ◽  
Dual Infections

African swine fever virus (ASFV) is one of the pathogens of highest concern worldwide. Despite different virus lineages co-circulating in several areas, dual infections in the same animal have been rarely observed, suggesting that ASF superinfections are infrequent events. Here we present the first genome-wide detection and analysis of two intragenotype dual ASFV infections. The dual infections have been detected in a hunted wild boar and in a pig carcass, both infected by ASFV genotype I in Sardinia in 1984 and 2018, respectively. We characterize the genetic differences between the two sequences, their intra-host frequency, and their phylogenetic relationship among fully sequenced ASFV strains from Sardinia. Both dual infections involve pairs of closely related but different viruses that were circulating in Sardinia in the same period. The results imply that dual ASFV infections or similar ASFV strains are more common than expected, especially in ASF endemic areas, albeit difficult to detect.

scholarly journals The first genotype II African swine fever virus isolated in Africa provides insight into the current Eurasian pandemic

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emma P. Njau ◽  
Jean-Baka Domelevo Entfellner ◽  
Eunice M. Machuka ◽  
Edwina N. Bochere ◽  
Sarah Cleaveland ◽  
...  
Keyword(s):  
Complete Genome ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Gene Families ◽  
Fever Virus ◽  
Eastern Africa ◽  
Chinese Isolate ◽  
Genome Sequences ◽  
Genotype I ◽  
Genotype Ii

AbstractAfrican swine fever (ASF) caused by the African swine fever virus (ASFV) is ranked by OIE as the most important source of mortality in domestic pigs globally and is indigenous to African wild suids and soft ticks. Despite two ASFV genotypes causing economically devastating epidemics outside the continent since 1961, there have been no genome-level analyses of virus evolution in Africa. The virus was recently transported from south-eastern Africa to Georgia in 2007 and has subsequently spread to Russia, eastern Europe, China, and south-east Asia with devastating socioeconomic consequences. To date, two of the 24 currently described ASFV genotypes defined by sequencing of the p72 gene, namely genotype I and II, have been reported outside Africa, with genotype II being responsible for the ongoing pig pandemic. Multiple complete genotype II genome sequences have been reported from European, Russian and Chinese virus isolates but no complete genome sequences have yet been reported from Africa. We report herein the complete genome of a Tanzanian genotype II isolate, Tanzania/Rukwa/2017/1, collected in 2017 and determined using an Illumina short read strategy. The Tanzania/Rukwa/2017/1 sequence is 183,186 bp in length (in a single contig) and contains 188 open reading frames. Considering only un-gapped sites in the pairwise alignments, the new sequence has 99.961% identity with the updated Georgia 2007/1 reference isolate (FR682468.2), 99.960% identity with Polish isolate Pol16_29413_o23 (MG939586) and 99.957% identity with Chinese isolate ASFV-wbBS01 (MK645909.1). This represents 73 single nucleotide polymorphisms (SNPs) relative to the Polish isolate and 78 SNPs with the Chinese genome. Phylogenetic analysis indicated that Tanzania/Rukwa/2017/1 clusters most closely with Georgia 2007/1. The majority of the differences between Tanzania/Rukwa/2017/1 and Georgia 2007/1 genotype II genomes are insertions/deletions (indels) as is typical for ASFV. The indels included differences in the length and copy number of the terminal multicopy gene families, MGF 360 and 110. The Rukwa2017/1 sequence is the first complete genotype II genome from a precisely mapped locality in Africa, since the exact origin of Georgia2007/1 is unknown. It therefore provides baseline information for future analyses of the diversity and phylogeography of this globally important genetic sub-group of ASF viruses.

Genetic markers of the African swine fever virus

2020 ◽  
Vol 23 (04) ◽  
pp. 21-26
Author(s):  
A.K. Sibgatullova ◽  
◽  
M.E. Vlasov ◽  
I.A. Titov ◽  
◽  
...  
Keyword(s):  
Genetic Markers ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus
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