Analysis of complete nucleotide sequences of Angolan hepatitis B virus isolates reveals the existence of a separate lineage within genotype E

PLoS One. 2014 Mar 14;9(3):e92223. doi: 10.1371/journal.pone.0092223. eCollection 2014.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antigens, Surface / genetics
  • Base Sequence
  • DNA-Directed DNA Polymerase / genetics
  • Genetic Variation
  • Genotype*
  • Hepatitis B virus / classification
  • Hepatitis B virus / genetics*
  • Hepatitis B virus / isolation & purification
  • Humans
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Mutation
  • Nucleotides / genetics*
  • Phylogeny
  • Young Adult

Substances

  • Antigens, Surface
  • Nucleotides
  • DNA-Directed DNA Polymerase

Associated data

  • GENBANK/HM195104
  • GENBANK/HM195106
  • GENBANK/HM195107
  • GENBANK/HM195109
  • GENBANK/HM195112
  • GENBANK/KF849713
  • GENBANK/KF849714
  • GENBANK/KF849715
  • GENBANK/KF849716
  • GENBANK/KF849717
  • GENBANK/KF849718
  • GENBANK/KF849719
  • GENBANK/KF849720
  • GENBANK/KF849721
  • GENBANK/KF849722
  • GENBANK/KF849723
  • GENBANK/KF849724
  • GENBANK/KF849725
  • GENBANK/KF849726
  • GENBANK/KF849727
  • GENBANK/KF849728
  • GENBANK/KF849729
  • GENBANK/KF849730
  • GENBANK/KF849731
  • GENBANK/KF849732
  • GENBANK/KF849733
  • GENBANK/KF849734
  • GENBANK/KF849735
  • GENBANK/KF849736
  • GENBANK/KF849737

Grants and funding

Sources of funding that have supported the work: Fiocruz, CNPq. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.