title: Phylogenetic analysis and subgenotypic distribution of the hepatitis B virus in Recife, Brazil.
abstract: The analysis of the genomes of the hepatitis B virus in human hosts identifies phylogenetic variants called viral genotypes. Indeed, clinical and epidemiological observations suggest that differences in viral genotypes lead to distinct biological and clinical behaviors. The aim of this study was to evaluate the subgenotypic distribution and to conduct a phylogenetic analysis by Bayesian method of the hepatitis B virus (HBV) in patients from Recife, Brazil. From July 2009 to December 2010, 60 HBV infected patients were examined, 39 (65%) were males, whose mean age was 50years old. 33 (55%) were genotyped by obtaining and amplifying a 1306bp fragment comprising part of the DNA polymerase and the surface antigen of the HBV. The sequencing was performed on an ABI 3500 Automatic Sequencer and the consensus sequences were obtained by aligning both the sequenced strands (clockwise and anti-clockwise) using SEQUENCHER software. Phylogenetic analysis was conducted using the Markov Chain Monte Carlo simulation implemented by Bayesian evolutionary method by sampling trees. The following subgenotypic distribution was observed: A1 (79%), F2a (12%), A2 (6%) and F4 (3%) as was that those identified as subgenotype A1 were in the same cluster in the phylogenetic tree. In this study, the majority of patients presented the A1 subgenotype from the same viral strain. As per the distribution in the phylogenetic tree by Bayesian method, possibly this subgenotype was in the genetic make-up of Africans brought in centuries past to Brazil as slaves.
authors.affiliation: Central Laboratory of the Hospital das Clínicas, Federal University of Pernambuco, Brazil.
authors.forename: Izolda Fernandes
authors.initials: IF
authors.lastname: Moura
authors.forename: Edmundo Pessoa
authors.initials: EP
authors.lastname: Lopes
authors.forename: Mónica Viviana
authors.initials: MV
authors.lastname: Alvarado-Mora
authors.forename: João Renato
authors.initials: JR
authors.lastname: Pinho
authors.forename: Flair José
authors.initials: FJ
authors.lastname: Carrilho
mesh_terms: D000328:Adult; D000368:Aged; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D005838:Genotype; D006509:Hepatitis B / Q000453:epidemiology; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010802:Phylogeny