Browsing by Author "Ajadi A."

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    Detection and molecular characterization of a first isolate of rabbit haemorrhagic disease virus in Nigeria
    (Springer, 2021) Daodu O.B.; Shaibu J.O.; Richards A.B.; Folaranmi E.B.; Adegoke S.; Ajadi A.; Olorunshola I.D.; Akanbi O.B.; Afolabi A.A.; Daodu O.C.; Aiyedun J.O.; Oludairo O.O.; Halleed N.I.; Audu R.A.; Oluwayelu D.O.
    Rabbit haemorrhagic disease virus (RHDV) was recovered from necropsied rabbits that died during an outbreak characterized by epistaxis, incoordination, paralysis, and multi-organ haemorrhages in Ilorin, Nigeria. The haemagglutination test (HA) and RT PCR assay targeted against a fragment of the RHDV VP60 gene were performed on liver, spleen, and kidney homogenates; faeces; and urine obtained from the rabbits. Amplicons were purified, sequenced, and phylogenetically analysed. The liver homogenates yielded the highest HA titres while RT-PCR of liver, spleen, and kidneys yielded the expected 1252 bp band. Sequence and phylogenetic analyses revealed that the Nigerian RHDV strain (RHDV/NGR/ILN/001) was 98.57%, 97.95%, and 96.70% homologous with RHDV2 (RHDVGI.2) strains from the Netherlands, Germany, and France, respectively. RHDV/NGR/ILN/001 induced tracheal, intestinal, and mediastinal lymph node haemorrhages, pulmonary oedema and congestion, and enlarged, necrotic liver in experimentally inoculated rabbits. The implications of this study, which is the first report of RHDV in Nigeria, are discussed
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    Pathology and immunohistochemical evaluation of Vibrio alginolyticus infection in Macrobrachium rosenbergii
    (Springer, 2019-12) Ajadi A.; Sabri M.Y.; Atata J.A.; Daodu O.B.; Emikpe B.O.
    Vibriosis is one of the common bacterial diseases plaguing the prawn and shrimp industry. However, the sequential histopathological changes associated with Vibrio alginolyticus-induced vibriosis is scanty in literature. This study investigated the histological alterations in groups of Macrobrachium rosenbergii experimentally injected intramuscularly between the second and third abdominal segment with 50 μL of 107 CFU of V. alginolyticus. Twenty-four hours post inoculation, the organism was isolated and molecularly characterized while infected giant freshwater prawns were observed for histological alterations and immunoreactivity in different tissues due to the experimental challenge. The lesions observed in the organs include incipient haemocytic infiltration into the interstitial space of the tubules of the hepatopancreas and loss of epithelial layer, muscular necrosis and disruption of muscular layer with haemocytic infiltration, hyperplasia of epithelial cells and degeneration of the epithelium, deformed and necrotizing lamellae, and enlargement of the lamellar sinus of the gill, and the heart is characterized by localized nodular haemocytic reaction and melanization. Organs such as the heart, gill, hepatopancreas and muscle following injection of the putative bacteria showed immunohistochemical activity. Hence, histology and immunohistochemistry still remain important tools for vibriosis disease diagnoses in giant freshwater prawns.
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    Surveillance for avian influenza virus in captive wild birds and indigenous chickens in Nigeria
    (Springer, 2020-03-20) Daodu O.B.; Jegede H.O.; Aiyedun J.O.; Oludairo O.O.; Olorunshola I.D.; Daodu O.C.; Ajadi A.; Ambali S.F.
    Several reports of avian influenza virus (AIV) have been made on commercial chickens and wild birds in sub-Saharan Africa, but there is paucity of information of AIV among captive wild birds and indigenous chickens. Blood samples were obtained randomly from captive wild birds and chickens. AIV nucleoprotein antibody detection involved the use of enzyme immunoassay (ELISA) and subsequent subtyping with H5 and H7 AIV antigens (haemagglutination inhibition). Four hundred birds belonging to nine families and 14 species were sampled, and overall prevalence of 23% (92/400) was obtained (captive wild birds (10.4%, 5/48), indigenous birds (47.3%, 87/184) and exotic commercial birds (0.0%, 0/168)). Twelve ELISA-positive birds (13.04%) were positive to H7 antigen. Univariate analysis indicated statistical significance of AIV prevalence in captive wild birds (p < 0.0001) and exotic birds (p < 0.0001) using indigenous chickens as reference. This study gave an evidence of exposure of captive wild birds and indigenous chickens to AIV in Nigeria. Scavenging activities common among indigenously raised chickens, unrestricted movement of nonflying wild birds within the captive complex and free access by migrating wild birds to captive wild birds and local chickens were likely factors observed to promote AIV transmission. Continuous surveillance can further highlight the roles played by these birds in the epidemiology of AIV