title: Hepatitis B virus genotypes and mutations in the basal core promoter and pre-core/core in chronically infected patients in southern Brazil: a cross-sectional study of HBV genotypes and mutations in chronic carriers.
abstract: BACKGROUND
  In Brazil, little data exist regarding the distribution of genotypes in relation to basal core promoter (BCP) and precore/core mutations among chronic hepatitis B virus (HBV) carriers from different regions of the country. The aim of this study was to identify HBV genotypes and the frequency of mutations at the BCP and precore/core region among the prevalent genotypes in chronic carriers from southern Brazil.
  
  
  METHODS
  Nested-polymerase chain reaction (nested-PCR) products amplified from the S-polymerase gene, BCP and precore/core region from 54 samples were sequenced and analyzed.
  
  
  RESULTS
  Phylogenetic analysis of the S-polymerase gene sequences showed that 66.7% (36/54) of the patients were infected with genotype D (D1, D2, D3), 25.9% (14/54) with genotype A (A1, A2), 5.6% (3/54) with subgenotype C2, and 2% (1/54) with genotype E. A comparison of virological characteristics showed significant differences between genotypes A, C and D. The comparison between HBeAg status and the G1896A stop codon mutation in patients with genotype D revealed a relationship between HBV G1896A precore mutants and genotype D and hepatitis B e antigen (HBeAg) seroconversion. Genotype D had a higher prevalence of the G1896A mutation and the presence of a thymine at position 1858. Genotype A was associated with a higher prevalence of the G1862T mutation and the presence of a cytosine at position 1858.
  
  
  CONCLUSIONS
  HBV genotype D (D3) is predominant in HBV chronic carriers from southern Brazil. The presence of mutations in the BCP and precore/core region was correlated with the HBV genotype and HBeAg negative status.
authors: Laboratório de Virologia Clínica, Departamento de Análises Clínicas e Biomedicina, Universidade Estadual de Maringá, Maringá, PR.
authors: Flávia Miryan Martins Almeida de
authors: FM
authors: Mello
authors: Consórcio Intermunicipal de Saúde do Setentrião Paranaense, Maringá, PR.
authors: Aline Satie Oba
authors: AS
authors: Kuniyoshi
authors: Laboratório de Virologia Clínica, Departamento de Análises Clínicas e Biomedicina, Universidade Estadual de Maringá, Maringá, PR.
authors: André Fanhani
authors: AF
authors: Lopes
authors: Laboratório de Gastroenterologia Tropical do Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors: Michele Soares
authors: MS
authors: Gomes-Gouvêa
authors: Laboratório de Virologia Clínica, Departamento de Análises Clínicas e Biomedicina, Universidade Estadual de Maringá, Maringá, PR.
authors: Dennis Armando
authors: DA
authors: Bertolini
mesh_terms: D000328:Adult; D001483:Base Sequence; D001938:Brazil; D002353:Carrier State / Q000821:virology*; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000032:analysis*; D005260:Female; D005838:Genotype; D006512:Hepatitis B Core Antigens; D006515:Hepatitis B virus / Q000235:genetics* / Q000276:immunology; D019694:Hepatitis B, Chronic / Q000821:virology*; D006801:Humans; D008297:Male; D009154:Mutation; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D004279:DNA, Viral; D006512:Hepatitis B Core Antigens