Browsing by Author "Adeniji JA"

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    Detection and circulation of hepatitis B virus immune escape mutants among asymptomatic community dwellers in Ibadan, southwestern Nigeria
    (2015) Faleye TO; Adewumi OM; Ifeorah IM; Akere A; Bakarey AS; Omoruyi EC; Oketunde K; Awonusi OB; Ajayi MR; Adeniji JA
    Background In 2012, the first Nigerian Hepatitis B Virus (HBV) immune escape mutant (IEM) case was detected in a pregnant woman in southwestern Nigeria. Consequently, this study was designed to investigate the presence and possible circulation of IEMs amongst asymptomatic community dwellers in southwestern Nigeria. Methods Blood specimens collected from 438 asymptomatic community dwellers were screened for HBsAg using ELISA technique. Subsequently, the S-gene was amplified in HBsAg positive samples by a nested PCR protocol, and amplicons sequenced. Isolates were then subtyped by amino acid residues at positions 122, 127, 134 and 160, and genotyped by phylogenetic analysis. Results Of the 31 (7.08%) samples positive for HBsAg, the ∼408bp Sgene fragment was successfully amplified and sequenced in 27. Samples obtained from 4 patients could not be amplified due to low titres. Sequence data from only 15 of the isolates could be analysed further as eight of the remaining 12 had multiple peaks while the rest three showed no similarity to any HBV gene when subjected to BLAST analysis. Thirteen of the 15 isolates were identified as genotype E. Eleven of which were subtyped as ayw4 while the remaining two could not be subtyped due to sR122Q/P substitutions. The last two isolates that could not be genotyped and subtyped had other mutations in the “a” determinant associated with IEMs. Conclusions This study confirmed presence and circulation of HBV IEM in Nigeria, the country's inclusion in the genotype E crescent, and the value of phylogenetic analysis in HBV identification.
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    Molecular characterization and evolutionary dynamics of measles virus sequences isolated from children in Lagos and Ibadan, South Western, Nigeria
    (2020) Faneye AO; Motayo BO; Adeniji JA
    Measles infection is endemic in Nigeria, with outbreaks occurring yearly. Genotype B3 is the dominant genotype and the only genotype characterized from Nigeria. The current study investigated the phylogenetic and Bayesian evolutionary dynamics of Nigerian measles virus Nucleoprotein (N) sequences isolated from Lagos and Ibadan, Nigeria. A total of 120 throat swab samples were analysed by RT-PCR and Sanger sequencing. Phylogenetic analysis and Bayesian demographic reconstructions were done using MEGA and BEAST software. Measles RNA positivity was 14.2% (17/120), age range 0–1 recorded the highest rate with 40.83%. Study sequences clustered within clade B3.1. The evolutionary rate of analysed B3 sequences was 1.108×10−3, higher posterior density HPD interval (1.462×10−3 – 7.886×10−4)subs/site/year. The time to most recent common ancestor (TMRC), was 1991. The Bayesian skyride analysis(BSP) of West African MV cladeB3.1, showed a stable, steady state population demography. This study has reemphasised the dominance of clade B3.1 in Nigeria. We have shown that clade B3.1 was recently introduced into circulation and has a slow population expansion. We advocate for the institution of molecular surveillance country wide in order to help monitor strain diversity and genetic evolution of Measles in Nigeria.