title: Related strains of African swine fever virus with different virulence: genome comparison and analysis.
abstract: Two strains of African swine fever virus (ASFV), the high-virulence Lisboa60 (L60) and the low-virulence NH/P68 (NHV), which have previously been used in effective immunization/protection studies, were sequenced. Both were isolated in Portugal during the 11-year period after the introduction of ASFV to the European Continent in 1957. The predicted proteins coded by both strains were compared, and where differences were found these were also compared to other strains of known virulence. This highlighted several genes with significant alterations in low-virulence strains of ASFV that may constitute virulence factors, several of which are still uncharacterized regarding their function. Phylogenetic analysis grouped L60 and NHV closest to other P72 genotype I ASFV strains from Europe and West Africa, consistent with the assumed West African origin of all European strains. Interestingly, a relatively lower genomic identity exists between L60 and NHV, both isolated in a similar geographical location 8 years apart, than with other European and west African strains isolated subsequently and in more distant locations. This may reflect the intensive passage in tissue culture, during the early 1960s, of a Portuguese isolate to obtain an attenuated vaccine, which may have led to NHV. This study contributes to a better understanding of the evolution of ASFV, and defines additional potential virulence genes for future studies of pathogenesis towards the development of effective vaccines.
authors.affiliation: Institut für molekulare Virologie und Zellbiologie, Friedrich-Loeffler-Institut, Greifswald-Insel Riems 17493, Germany.
authors.forename: Raquel
authors.initials: R
authors.lastname: Portugal
authors.affiliation: Centro de Investigação Interdisciplinar em Sanidade Animal (CIISA), Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, Lisboa 1300-477, Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Coelho
authors.affiliation: Institut für molekulare Virologie und Zellbiologie, Friedrich-Loeffler-Institut, Greifswald-Insel Riems 17493, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Höper
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria BC, Canada.
authors.forename: Nicole S
authors.initials: NS
authors.lastname: Little
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria BC, Canada.
authors.forename: Chad
authors.initials: C
authors.lastname: Smithson
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria BC, Canada.
authors.forename: Chris
authors.initials: C
authors.lastname: Upton
authors.affiliation: Centro de Investigação Interdisciplinar em Sanidade Animal (CIISA), Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, Lisboa 1300-477, Portugal.
authors.forename: Carlos
authors.initials: C
authors.lastname: Martins
authors.affiliation: Instituto de Investigação Científica Tropical, CVZ, FMV, Avenida da Universidade Técnica, Lisboa 1300-477, Portugal.|Centro de Investigação Interdisciplinar em Sanidade Animal (CIISA), Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, Lisboa 1300-477, Portugal.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Leitão
authors.affiliation: Institut für molekulare Virologie und Zellbiologie, Friedrich-Loeffler-Institut, Greifswald-Insel Riems 17493, Germany.
authors.forename: Günther M
authors.initials: GM
authors.lastname: Keil
mesh_terms: D000358:African Swine Fever Virus / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification* / Q000502:physiology*; D000818:Animals; D016000:Cluster Analysis; D004279:DNA, Viral / Q000235:genetics; D019143:Evolution, Molecular; D016679:Genome, Viral; D008969:Molecular Sequence Data; D010802:Phylogeny; D011174:Portugal; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013552:Swine; D014764:Viral Proteins / Q000235:genetics; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins; D037521:Virulence Factors