A novel variant genotype C of hepatitis B virus identified in isolates from Australian Aborigines: complete genome sequence and phylogenetic relatedness

• Published in: Journal of general virology Vol. 82; no. 4; pp. 883 - 892
• Main Authors: Sugauchi, Fuminaka, Mizokami, Masashi, Orito, Etsuro, Ohno, Tomoyoshi, Kato, Hideaki, Suzuki, Seiji, Kimura, Yoshihide, Ueda, Ryuzo, Butterworth, L. A, Cooksley, W. G. E
• Format: Journal Article
• Language: English
• Published: England Soc General Microbiol 01.04.2001
• Subjects: Amino Acid Sequence; Animals; Australia; Genotype; hepatitis B surface antigen; Hepatitis B Surface Antigens - analysis; Hepatitis B virus; Hepatitis B virus - classification; Hepatitis B virus - genetics; Humans; Molecular Sequence Data; Oceanic Ancestry Group; Phylogeny; Serotyping; small-S gene; Australia
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-82-4-883

Second Department of Internal Medicine 1 and Laboratory Medicine 2 , Nagoya City University Medical School, Kawasumi, Mizuho, 467-8601 Nagoya, Japan Royal Brisbane Hospital Research Foundation, Brisbane, Australia 3 Author for correspondence: Masashi Mizokami. Fax +81 52 842 0021. e-mail mizokami{at}med.nagoya-cu.ac.jp There have been no reports of DNA sequences of hepatitis B virus (HBV) strains from Australian Aborigines, although the hepatitis B surface antigen (HBsAg) was discovered among them. To investigate the characteristics of DNA sequences of HBV strains from Australian Aborigines, the complete nucleotide sequences of HBV strains were determined and subjected to molecular evolutionary analysis. Serum samples positive for HBsAg were collected from five Australian Aborigines. Phylogenetic analysis of the five complete nucleotide sequences compared with DNA sequences of 54 global HBV isolates from international databases revealed that three of the five were classified into genotype D and were most closely related in terms of evolutionary distance to a strain isolated from a healthy blood donor in Papua New Guinea. Two of the five were classified into a novel variant genotype C, which has not been reported previously, and were closely related to a strain isolated from Polynesians, particularly in the X and Core genes. These two strains of variant genotype C differed from known genotype C strains by 5·9–7·4% over the complete nucleotide sequence and 4·0–5·6% in the small-S gene, and had residues Arg 122 , Thr 127 and Lys 160 , characteristic of serotype ayw3 , which have not been reported previously in genotype C. In conclusion, this is the first report of the characteristics of complete nucleotide sequences of HBV from Australian Aborigines. These results contribute to the investigation of the worldwide spread of HBV, the relationship between serotype and genotype and the ancient common origin of Australian Aborigines.