Phylogenetic tree of 37 HBV isolates, constructed with the neighbor-joining method, and based on 200 nucleotides (positions 1814-2013). Capital letters A, D, and C designate the respective genotype groupings. Bootstrap values were calculated from 100 replicates and the numbers above 60 are shown. Isolates A1 to A17, D1 to D9, and F1 to F3 are from this work. Their nucleotide sequences have been deposited in the Genbank database under accession numbers AF389988 to AF390016. The other isolates are designated by their Genbank accession numbers.