Molecular Cloning and Restriction Enzyme Mapping of an African Swine Fever Virus Isolate from Malawi

This study aimed to indicate the influence of infection caused by genotype II African swine fever virus (ASFV)–isolate Pol18_28298_O111, currently circulating in Poland, on blood counts, biochemical parameters, as well as inflammatory and immune responses. Blood and sera collected from 21 domestic pigs infected intranasally with different doses of virulent ASFV were analysed. The infection led to variable changes in blood counts depending on the stage of the disease with a tendency towards leukopenia and thrombocytopenia. The elevated C-reactive protein (CRP) concentrations and microscopic lesions in organs confirmed the development of the inflammation process, which also resulted in an increased level of biochemical markers such as: Aspartate transaminase (AST), creatine kinase (CK), creatinine, and urea. Antibodies could be detected from 9 to 18 days post infection (dpi). Two survivors presented the highest titer of antibodies (>5 log10/mL) with a simultaneous increase in the lymphocyte T (CD3+) percentage–revealed by flow cytometry. Results confirmed a progressive inflammatory process occurring during the ASFV infection, which may lead to multiple organs failure and death of the majority of affected animals.

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Different routes and doses influence protection in pigs immunised with the naturally attenuated African swine fever virus isolate OURT88/3

Antiviral Research ◽

10.1016/j.antiviral.2016.11.021 ◽

2017 ◽

Vol 138 ◽

pp. 1-8 ◽

Cited By ~ 29

Author(s):

Pedro J. Sánchez-Cordón ◽

Dave Chapman ◽

Tamara Jabbar ◽

Ana L. Reis ◽

Lynnette Goatley ◽

...

Keyword(s):

Virus Isolate ◽

African Swine Fever Virus ◽

African Swine Fever ◽

Fever Virus

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Characterization of pathogenic and non-pathogenic African swine fever virus isolates from Ornithodoros erraticus inhabiting pig premises in Portugal

Journal of General Virology ◽

10.1099/vir.0.80058-0 ◽

2004 ◽

Vol 85 (8) ◽

pp. 2177-2187 ◽

Cited By ~ 85

Author(s):

F. S. Boinas ◽

G. H. Hutchings ◽

L. K. Dixon ◽

P. J. Wilkinson

Keyword(s):

Restriction Enzyme ◽

African Swine Fever Virus ◽

African Swine Fever ◽

Fever Virus ◽

Restriction Enzyme Site ◽

Lower Efficiency ◽

Terminal Fragment ◽

Site Mapping ◽

The Right ◽

Virus Isolates

Ten African swine fever virus isolates from the soft tick Ornithodoros erraticus collected on three farms in the province of Alentejo in Portugal were characterized by their ability to cause haemadsorption (HAD) of red blood cells to infected pig macrophages, using restriction enzyme site mapping of the virus genomes and by experimental infection of pigs. Six virus isolates induced haemadsorption and four were non-haemadsorbing (non-HAD) in pig macrophage cell cultures. The restriction enzyme site maps of two non-HAD viruses, when compared with a virulent HAD isolate, showed a deletion of 9·6 kbp in the fragment adjacent to the left terminal fragment and of 1·6 kbp in the right terminal fragment and an insertion of 0·2 kbp in the central region. The six HAD viruses isolated were pathogenic and produced typical acute African swine fever in pigs and the four non-HAD isolates were non-pathogenic. Pigs that were infected with non-HAD viruses were fully resistant or had a delay of up to 14 days in the onset of disease, after challenge with pathogenic Portuguese viruses. Non-HAD viruses could be transmitted by contact but with a lower efficiency (42–50 %) compared with HAD viruses (100 %). The clinical differences found between the virus isolates from the ticks could have implications for the long-term persistence of virus in the field because of the cross-protection produced by the non-pathogenic isolates. This may also explain the presence of seropositive pigs in herds in Alentejo where no clinical disease had been reported.

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Nucleotide sequence of a 55 kbp region from the right end of the genome of a pathogenic African swine fever virus isolate (Malawi LIL20/1)

Journal of General Virology ◽

10.1099/0022-1317-75-7-1655 ◽

1994 ◽

Vol 75 (7) ◽

pp. 1655-1684 ◽

Cited By ~ 40

Author(s):

L. K. Dixon ◽

S. R. F. Twigg ◽

S. A. Baylis ◽

S. Vydelingum ◽

C. Bristow ◽

...

Keyword(s):

Nucleotide Sequence ◽

Virus Isolate ◽

African Swine Fever Virus ◽

African Swine Fever ◽

Fever Virus ◽

The Right

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Molecular cloning of African swine fever virus DNA

Virology ◽

10.1016/0042-6822(84)90392-1 ◽

1984 ◽

Vol 133 (2) ◽

pp. 249-257 ◽

Cited By ~ 35

Author(s):

V. Ley ◽

J.M. Almendral ◽

P. Carbonero ◽

A. Beloso ◽

E. Viñuela ◽

...

Keyword(s):

Molecular Cloning ◽

African Swine Fever Virus ◽

African Swine Fever ◽

Fever Virus

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Attempts at the development of a recombinant African swine fever virus strain with abrogated EP402R, 9GL, and A238L gene structure using the CRISPR/Cas9 system

Journal of Veterinary Research ◽

10.2478/jvetres-2020-0039 ◽

2020 ◽

Vol 64 (2) ◽

pp. 197-205 ◽

Cited By ~ 2

Author(s):

Grzegorz Woźniakowski ◽

Natalia Mazur-Panasiuk ◽

Marek Walczak ◽

Małgorzata Juszkiewicz ◽

Maciej Frant ◽

...

Keyword(s):

Immune Response ◽

Cell Lines ◽

Virus Isolate ◽

African Swine Fever Virus ◽

African Swine Fever ◽

Host Immune Response ◽

Economic Problem ◽

Fever Virus ◽

Established Cell Lines ◽

Established Cell

AbstractIntroductionAfrican swine fever (ASF) is a pressing economic problem in a number of Eastern European countries. It has also depleted the Chinese sow population by 50%. Managing the disease relies on culling infected pigs or hunting wild boars as sanitary zone creation. The constraints on the development of an efficient vaccine are mainly the virus’ mechanisms of host immune response evasion. The study aimed to adapt a field ASFV strain to established cell lines and to construct recombinant African swine fever virus (ASFV) strain.Material and MethodsThe host immune response modulation genes A238L, EP402R, and 9GL were deleted using the clustered regularly interspaced short palindromic repeats/caspase 9 (CRISPR/Cas9) mutagenesis system. A representative virus isolate (Pol18/28298/Out111) from Poland was isolated in porcine primary pulmonary alveolar macrophage (PPAM) cells. Adaptation of the virus to a few established cell lines was attempted. The plasmids encoding CRISPR/Cas9 genes along with gRNA complementary to the target sequences were designed, synthesised, and transfected into ASFV-infected PPAM cells.ResultsThe reconstituted virus showed similar kinetics of replication in comparison to the parent virus isolate.ConclusionTaking into account the usefulness of the developed CRISPR/Cas9 system it has been shown that modification of the A238L, EP402R, and 9GL genes might occur with low frequency, resulting in difficulties in separation of various virus populations.

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