Generation of duck hepatitis B virus polymerase mutants through site-directed mutagenesis which demonstrate resistance to lamivudine [(-)-beta-L-2',3'-dideoxy-3'-thiacytidine] in vitro

Hepatitis B virus replication is very sensitive to lamivudine. A single amino acid change in the human immunodeficiency virus reverse transcriptase is responsible for high-level resistance to this compound. Duck hepatitis B virus mutants were created bearing the analogous amino acid change in the duck hepatitis B virus polymerase. Viral DNA production was reduced 92% for the wild-type virus at 2 mu g of lamivudine per ml, while the mutants required 40 mu g of lamivudine per ml to inhibit replication by greater than 80%.