title: Analysis of complete nucleotide sequences of Angolan hepatitis B virus isolates reveals the existence of a separate lineage within genotype E.
abstract: Hepatitis B virus genotype E (HBV/E) is highly prevalent in Western Africa. In this work, 30 HBV/E isolates from HBsAg positive Angolans (staff and visitors of a private hospital in Luanda) were genetically characterized: 16 of them were completely sequenced and the pre-S/S sequences of the remaining 14 were determined. A high proportion (12/30, 40%) of subjects tested positive for both HBsAg and anti-HBs markers. Deduced amino acid sequences revealed the existence of specific substitutions and deletions in the B- and T-cell epitopes of the surface antigen (pre-S1- and pre-S2 regions) of the virus isolates derived from 8/12 individuals with concurrent HBsAg/anti-HBs. Phylogenetic analysis performed with 231 HBV/E full-length sequences, including 16 from this study, showed that all isolates from Angola, Namibia and the Democratic Republic of Congo (n = 28) clustered in a separate lineage, divergent from the HBV/E isolates from nine other African countries, namely Cameroon, Central African Republic, Côte d'Ivoire, Ghana, Guinea, Madagascar, Niger, Nigeria and Sudan, with a Bayesian posterior probability of 1. Five specific mutations, namely small S protein T57I, polymerase Q177H, G245W and M612L, and X protein V30L, were observed in 79-96% of the isolates of the separate lineage, compared to a frequency of 0-12% among the other HBV/E African isolates.
authors.affiliation: Laboratory of Molecular Virology, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Barbara V
authors.initials: BV
authors.lastname: Lago
authors.affiliation: Laboratory of Molecular Virology, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Francisco C
authors.initials: FC
authors.lastname: Mello
authors.affiliation: Laboratory of Molecular Virology, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Flavia S
authors.initials: FS
authors.lastname: Ribas
authors.affiliation: Eduardo dos Santos Foundation, Ministry of Health, Luanda, Angola.
authors.forename: Fatima
authors.initials: F
authors.lastname: Valente
authors.affiliation: Laboratory of Molecular Virology, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Caroline C
authors.initials: CC
authors.lastname: Soares
authors.affiliation: Laboratory of Molecular Virology, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Christian
authors.initials: C
authors.lastname: Niel
authors.affiliation: Laboratory of Molecular Virology, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Selma A
authors.initials: SA
authors.lastname: Gomes
mesh_terms: D000328:Adult; D000368:Aged; D000954:Antigens, Surface / Q000235:genetics; D001483:Base Sequence; D004259:DNA-Directed DNA Polymerase / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D006515:Hepatitis B virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D009711:Nucleotides / Q000235:genetics*; D010802:Phylogeny; D055815:Young Adult
chemical_list: D000954:Antigens, Surface; D009711:Nucleotides; D004259:DNA-Directed DNA Polymerase