Results
Postmortem examination revealed splenomegaly and severe congestion 2/2
(figure 1), enlarged and haemorrhagic lymphnodes 2/2 (figure 2),
hepatomegaly and severe congestion ½ (figure 3a), white multi-focal
patches on the liver ½ (figure 3b), globosed, severely congested,
generalized cortical petechiae and severe blood clot in the pelvis 2/2
(figures 4a and b). Histopathological findings were thus: spleen: severe
lymphocytes depletion (figure 5). Lymph node: severe lymphocytes
depletion and severe hemosiderosis (figure 6). Liver: severe congestion
with focal areas of coagulation necrosis (figure 7). Kidney: severe
congestion and renal tubular and glomerular necrosis with few tubular
proteins cast (figures 8a and b).
Viral isolation on the culture plate was revealed by haemadsorption. The
presence of the virus typified by the attachment of large numbers of pig
erythrocytes to the surface of infected cells thereby forming the
rosette appearance (figure 9) as opposed to the negative wells which
were not inoculated with the infected tissues (figure 10).
Gel picture (Figure 11) shows that DNA fragments of 278bp (confirming
the presence of ASFV) were successfully extracted and amplified from the
spleen, lymph node and kidney of the infected animals. Note that the
size of the PCR products in lanes 1, 2, and 3, which were ASFV positive
amplicons presented similar DNA fragment base pairs to the product of
the positive control of ASFV in lane 4. The nucleotide sequences of ASFV
generated from this study were deposited in the Genbank with accession
numbers MN888963 and MN888964.
The result of phylogenetic analysis based on the p72 (B646L) gene is
presented in figure 12. It shows the ancestral relatedness of the
sequence from this study to other 53 sequences downloaded from the
Genbank database, including those from Nigeria, different parts of
Africa and beyond. Apparently, the sequence from this study failed to
cluster with any other, including the ones from Nigeria. However, the
closest relatives based on the phylogenetic analysis are sequences that
make up the genotype-I ASFV group. These sequences were generated mainly
from Nigeria, other countries (especially Western and Central Africa),
and Europe. Consequently, the sequence from this study was considered to
also belong to genotype-I ASFV.