RESUMO
<p><b>OBJECTIVE</b>[corrected] To assess the specificity and applicability of direct PCR sequencing in the detection of point mutations in hepatitis B virus (HBV) associated with drug resistance.</p><p><b>METHODS</b>Serum samples were obtained from 120 patients with hepatitis B treated with nucleoside analogus for at least 2 years to detect the point mutations in HBV genome in association with drug resistance using nested PCR and direct DNA sequencing.</p><p><b>RESULTS</b>Forty out of the 120 patients were found to have one or two point mutations associated with drug resistance, including 17 with L180M and M204V/I mutations (42.5%), 10 with M204V/I mutation (25%), 8 with N236T mutation (20%), 3 with L180M mutation (7.5%), and 1 with both A181V/T and N236T mutations (2.5%), and 1 with A181V/T mutation(2.5%).</p><p><b>CONCLUSION</b>DNA sequencing is a good method to detect all known point mutations associated with HBV drug resistance.</p>