title: Identification and characterization of genotype A and D recombinant hepatitis B virus from Indian chronic HBV isolates.
abstract: OBJECTIVE
  To confirm the presence of recombination, full-length hepatitis B virus (HBV) from chronic patients was sequenced and analyzed.
  
  
  METHODS
  Full-length HBV genomes from 12 patients were amplified and sequenced in an automated sequencer. Phylogenetic analysis was carried out on full-length, Core and preS2/Surface regions using MEGA software. SimPlot Boot Scanning and amino acid sequence analysis were performed for confirmation of recombination.
  
  
  RESULTS
  Eight patients were infected with genotype D strain; one patient with genotype A and three patients had genotype A and D recombination; two of them had cirrhosis and one had hepatocellular carcinoma. Phylogenetic analysis of core and preS2/surface regions separately showed evidence of genotype A and D recombination. The breakpoints of recombination were found to be at the start of preS2 and at the end of surface coding regions.
  
  
  CONCLUSIONS
  We identified and characterized recombinant A and D genotype HBV in hepatitis B surface antigen (HBsAg)-positive patients.
authors.affiliation: Department of Gastroenterology, G. B. Pant Hospital, Delhi University Affiliated, Room No. 201, Academic Block, New Delhi 110002, India.
authors.forename: Ranjit
authors.initials: R
authors.lastname: Chauhan
authors.forename: Syed-Naqui
authors.initials: SN
authors.lastname: Kazim
authors.forename: Manoj
authors.initials: M
authors.lastname: Kumar
authors.forename: Jayashree
authors.initials: J
authors.lastname: Bhattacharjee
authors.forename: Narayanasamy
authors.initials: N
authors.lastname: Krishnamoorthy
authors.forename: Shiv-Kumar
authors.initials: SK
authors.lastname: Sarin
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D006528:Carcinoma, Hepatocellular / Q000821:virology; D002648:Child; D004252:DNA Mutational Analysis; D004279:DNA, Viral; D005260:Female; D005838:Genotype; D006512:Hepatitis B Core Antigens / Q000235:genetics; D006514:Hepatitis B Surface Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000145:classification / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000150:complications / Q000821:virology*; D006801:Humans; D007194:India; D008103:Liver Cirrhosis / Q000821:virology; D008113:Liver Neoplasms / Q000821:virology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D016366:Open Reading Frames; D010802:Phylogeny; D011498:Protein Precursors / Q000235:genetics; D011995:Recombination, Genetic; D055815:Young Adult
chemical_list: D004279:DNA, Viral; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D011498:Protein Precursors; C050807:presurface protein 2, hepatitis B surface antigen