en Molecular Microbiology Molecular Microbiology مقاله کامل Full Length/Original Article <strong>Background: </strong>Genetic changeability of hepatitis B virus (HBV) signifies a challenge for the sensitivity of immunologic and molecular diagnostics. Therefore, knowing the spread of HBV genotypes (GENs) and mutation has considerable impacts on treatment strategies, vaccination program, diagnosis, and prevention. The present study aimed to detect HBV GENs and mutants in HBsAg-positive patients. <strong>Methods:</strong> The study conducted on 4927 patients in Meerut, India, between March 2013 and April 2017. The blood specimens were analyzed for HBsAg using an ELISA kit, then the blood samples from HBsAg-positive patients were subjected to HBeAg assay and DNA isolation. Amplification of the HBV DNA of pre-S gene and pre-core or basal core promoter region were performed by RT-PCR and sequenced to analyze both GEN and mutation. <strong>Results: </strong>According to the results, 245 cases were positive for HBsAg, and 55 were HBeAg-positive. With regard to HBV DNA levels, 16 samples were found positive in PCR assay with 7 (43.8%) less than 2000 IU/mL, 4 (25%) between >2000 and 20,000 IU/mL, and 5 (3.25%) >20,000 IU/mL. No mutations were detected in GENs B and A. The prevalence of HBV GENs B and A were 68.8% (n = 11) and 31.25% (n = 6), respectively. <strong>Conclusion:</strong> GEN-B was more prevalent in comparison to GEN-A. The genetic diversity of HBV and distribution of its GENs and mutation improve the current knowledge of epidemiological, clinical and virological patterns of hepatitis B in this region, which help physicians to prescribe proper antiviral/interferon therapy according to current genotyping pattern.&nbsp; Genotype, Hepatitis B surface antigens, Hepatitis B virus, India, Mutation 354 361 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-1-767&slc_lang=en&sid=1 Salman Khan Yes Department of Microbiology, Netaji Subhash Chandra Bose Subharti Medical College, Swami Vivekanand Subharti University, Meerut, Uttar Pradesh, India Molly Madan No Department of Microbiology, Netaji Subhash Chandra Bose Subharti Medical College, Swami Vivekanand Subharti University, Meerut, Uttar Pradesh, India Sunil Kumar Virmani No Department of Medicine, Netaji Subhash Chandra Bose Subharti Medical College, Swami Vivekanand Subharti University, Meerut, Uttar Pradesh, India