Molecular characterisation of African swine fever viruses from Nigeria (2003–2006) recovers multiple virus variants and reaffirms CVR epidemiological utility
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Samples collected from wild and domestic suids in Nigeria, over a 3-year period (2003–2006), were evaluated for African swine fever (ASF) virus genome presence by targeting three discrete genome regions, namely the 478-bp C-terminal p72 gene region advocated for genotype assignment, a 780-bp region spanning the 5′-ends of the pB125R and pB646L (p72) genes and the hypervariable central variable region (CVR) encoded within the 9RL ORF (pB602L). ASF virus (ASFV) presence was confirmed in 23 of the 26 wild and domestic pigs evaluated. No evidence of ASF infection was found in two warthogs from Adamawa State; however, one bushpig from Plateau State was positive. Nucleotide sequences of the 478-bp and 780-bp amplicons were identical across all ASFV-positive samples sequenced. However, five discrete CVR variants were recovered, bringing the total number identified to date, from Nigeria, to six. The largest of the CVR variants, termed ‘Tet-36’ was identical to a virus causing outbreaks in neighbouring Benin in 1997, indicating a prolonged persistence of this virus type in Nigeria. Co-circulation of three tetramer types (Tet-36, Tet-27 and Tet-20) was found in Plateau State in July 2004, whilst in Benue State, two tetramer types (Tet-20 and Tet-21) were present in August 2005. Despite simultaneous field presence, individual co-infection was not observed. This study has reaffirmed the epidemiological utility of the CVR genome region for distinguishing between geographically and temporally constrained genotype I viruses, and has revealed the presence of multiple ASFV variants in Nigeria.
Keywordsp72 CVR Sequencing Phylogeny Domestic pig Bushpig
We are grateful to the Knowledge Interchange & Collaboration: Focus on Africa Interaction Travel programme of the National Research Foundation (NRF) South Africa, for supporting Dr. Owolodun’s 2006 research visit to South Africa.
- 4.M.-L. Penrith, G.R. Thomson, A.D.S. Bastos, in Infectious Diseases of Livestock with Special Reference to Southern Africa, ed. by J.A.W. Coetzer, R.C. Tustin (Oxford University Press, Cape Town, 2004), pp. 1087–1119Google Scholar
- 5.F. Jori, A.D.S. Bastos, EcoHealth (2009). doi: 10.1007/s10393-009-0248-7
- 7.N.J. Luther, P.G. Udeama, K.A. Majiyagbe, D. Shamaki, J. Antiabong, Y. Bitrus, C.I. Nwosuh, O.A. Owolodun, Niger. Vet. J. 28, 63–67 (2007)Google Scholar
- 8.R.E. Montgomery, J. Comp. Pathol. 34, 159–191 (1921)Google Scholar
- 14.E.B. Otesile, A.T.P. Ajuwape, S.O. Odemuyiwa, S.O. Akpavie, A.K. Olaifa, G.N. Odaibo, O.D. Olaleye, A.I. Adetosoye, Rev. Elev. Med. Vet. Pays Trop. 58, 21–26 (2005)Google Scholar
- 16.O.A. Owolodun, B. Yakubu, J.F. Antiabong, O.K. Adefalujo, M.E. Ogedengbe, E.T. Obisakin, D. Shamaki, Bull. Anim. Health. Prod. Afr. 55, 96–103 (2007)Google Scholar
- 22.D.L. Swofford, PAUP*. Phylogenetic Analysis Using Parsimony (*and other methods). Version 4.10 (Sinauer Associates Inc., MA, USA, 2003)Google Scholar