AIM: To evaluate the genotype distribution of hepatitis B virus (HBV) in Eastern India and to clarify the phyloge- netic origin and virological characteristics of the recently identifi ed genotype C in this region. ME...AIM: To evaluate the genotype distribution of hepatitis B virus (HBV) in Eastern India and to clarify the phyloge- netic origin and virological characteristics of the recently identifi ed genotype C in this region. METHODS: Genotype determination, T1762/A1764 mutation in the basal core promoter (BCP) and A1896 mutation in the precore region of 230 subjects were de- termined by restriction fragment length polymorphism method (RFLP) and the result was confi rmed by direct sequencing. RESULTS: The predominant genotypes D (HBV/D) and A (HBV/A) were detected in 131/230 (57%) and 57/230 (25%) samples. In addition, genotype C (HBV/C) was detected in 42/230 (18%) isolates. Surface gene region was sequenced from 45 isolates (27 HBV/C, 9 HBV/A and 9 HBV/D). Phylogenetic analysis revealed that all of the HBV/C sequences clustered with South East Asian subgenotype (HBV/Cs). The sequence data showed re- markable similarity with a Thai strain (AF068756) (99.5% ± 0.4% nucleotide identities) in 90% of the genotype C strains analyzed. T1762/A1764 mutation in BCP re- gion, associated with high ALT was signifi cantly higher in HBeAg negative isolates than HBeAg positive isolates. Frequency of A1896 mutation leading to HBeAg negativ- ity was low.CONCLUSION: The present study reports the genotypic distribution and the characteristics of partial genome sequences of HBV/C isolates from Eastern India. Low genetic diversity and confi nement of HBV/C in Eastern India possibly indicate a recent, limited, spread in this region. Genotype C with T1762/A1764 mutation has been reported to increase the risk for hepatocellular car- cinoma; therefore genotype C carriers in Eastern India should be carefully monitored.展开更多
基金Supported by Indian Council of Medical Research, Government of India. Arup Banerjee and Sibnarayan Datta are recipient of senior research fellowship of the Indian Council of Medical Research and University Grants Commission, Government of India, respectively
文摘AIM: To evaluate the genotype distribution of hepatitis B virus (HBV) in Eastern India and to clarify the phyloge- netic origin and virological characteristics of the recently identifi ed genotype C in this region. METHODS: Genotype determination, T1762/A1764 mutation in the basal core promoter (BCP) and A1896 mutation in the precore region of 230 subjects were de- termined by restriction fragment length polymorphism method (RFLP) and the result was confi rmed by direct sequencing. RESULTS: The predominant genotypes D (HBV/D) and A (HBV/A) were detected in 131/230 (57%) and 57/230 (25%) samples. In addition, genotype C (HBV/C) was detected in 42/230 (18%) isolates. Surface gene region was sequenced from 45 isolates (27 HBV/C, 9 HBV/A and 9 HBV/D). Phylogenetic analysis revealed that all of the HBV/C sequences clustered with South East Asian subgenotype (HBV/Cs). The sequence data showed re- markable similarity with a Thai strain (AF068756) (99.5% ± 0.4% nucleotide identities) in 90% of the genotype C strains analyzed. T1762/A1764 mutation in BCP re- gion, associated with high ALT was signifi cantly higher in HBeAg negative isolates than HBeAg positive isolates. Frequency of A1896 mutation leading to HBeAg negativ- ity was low.CONCLUSION: The present study reports the genotypic distribution and the characteristics of partial genome sequences of HBV/C isolates from Eastern India. Low genetic diversity and confi nement of HBV/C in Eastern India possibly indicate a recent, limited, spread in this region. Genotype C with T1762/A1764 mutation has been reported to increase the risk for hepatocellular car- cinoma; therefore genotype C carriers in Eastern India should be carefully monitored.
