Molecular characterization of hepatitis B virus X gene in HIV-positive South Africans.
Hepatitis B virus (HBV) infection is a major public health problem worldwide and the major cause of hepatocellular carcinoma (HCC) in South Africa. The role of HBV in HCC is not well understood, although the HBV X gene has been implicated as a critical factor. Data on the HBV X gene in HIV-positive South Africans are limited; thus, we investigated X gene variability in 24 HIV-infected treatment-naïve patients at Dr George Mukhari Academic Hospital. Quantitative and qualitative HBV DNA tests were conducted using real-time and in-house polymerase chain reaction (PCR) assays, respectively, targeting the complete HBV X gene. In-house PCR-positive samples were cloned using the P-Gem T-easy vector System II and sequenced. By phylogenetic analysis, X gene sequences were classified as subgenotype A1 (n = 15), A2 (n = 4), and D1 (n = 4), and one dual infection with subgenotypes as A1 and C. The basal core promoter mutations T1753C, A1762T, and G1764A were identified in the majority of sequences. Genotype D sequences had a 6-nucleotide insertion. In conclusion, subgenotype A1 was predominant, and a rare dual infection of HBV genotype A and C was detected. The 6-nucleotide insertion could represent a unique variant in the region and highlights the need for functional studies of HBV X gene variants, particularly from resource-limited settings.
['Gededzha|Maemu P|MP|', 'Sondlane|Tsakani H|TH|', 'Malinga|Lesibana A|LA|', 'Burnett|Rosemary J|RJ|', 'Lebelo|Ramokone L|RL|', 'Blackard|Jason T|JT|', 'Mphahlele|M Jeffrey|MJ|', 'Selabe|Selokela G|SG|']
D016000:Cluster Analysis D014644:Genetic Variation D005838:Genotype D015658:HIV Infections D006515:Hepatitis B virus D019694:Hepatitis B, Chronic D006761:Hospitals D006801:Humans D009154:Mutation D010802:Phylogeny D016133:Polymerase Chain Reaction D011401:Promoter Regions, Genetic D017422:Sequence Analysis, DNA D017385:Sequence Homology D013019:South Africa D015534:Trans-Activators D054334:Viral Regulatory and Accessory Proteins
Hepatitis B virus (HBV) South Africa Africa Genotype HBx HIV