Abstract: Objective To analyze the genotypes and mutation sites of hepatitis B virus (HBV) associated with drug resistance. Methods A retrospective analysis was conducted in HBV genotypes, nucleoside drugs (NAs) resistance including lamivudine (LAM), telbivudine (LdT), adefovir dipivoxil (ADV) and entecavir (ETV). Drug resistance mutations, HBV DNA, HBeAg, alanine aminotransferase (ALT) and platelet (PLT) were detected in 114 patients with hepatitis B between 2014 and 2016. Results Sixty-one of 114 patients were found to carrywith HBV genotype C, 45 with genotype B, 3 with genotype D, one with recombinant B/C, one with recombinant B/D and 5 with other genotypes. Type C had a high frequency (P<0.05). Thirty-nine(34.21%) cases carried NAs resistance mutations. No significant difference of NAs resistance mutations was seen between types C and B. The patients with type C had significantly decreased HBeAg (P<0.05) and low PLT(P<0.05) compared with type B.The most common drug resistance mutation was found in rt204I. Multilocus mutation of type C was more commonly detectable than that of type B (P<0.05). The combinated resistance of HBV to LAM and LdT, and two or more multiple drug resistance weremost common (P<0.01). Conclusion The genotype C of HBV dominated in this study, followed by genotype B. Patients with genotype C are prone to hepatic fibrosis and multiple site mutations, and the HBV resistance was frequently noted to LAM and LdT. The results indicated that HBV genotyping and drug resistance mutation detectionmay help evaluatethe clinical efficacy of antiviral therapy.

Key words: Hepatitis B virus, HBV genotype, Drug resistance mutations, Nucleoside drugs