Eighth major clade for hepatitis delta virus

Abstract

Hepatitis delta virus is the only representative of the Deltavirus genus, which consists of 7 differentiated major clades. In this study, an eighth clade was identified from 3 distinct strains. Deltavirus genetic variability should be considered for diagnostic purposes. Clinical consequences of the diversity have yet to be evaluated.

Figure 1

Percent similarity between hepatitis delta virus (HDV) genotypes calculated from complete and small hepatitis delta (sHD) nucleotide sequences. Above the oblique line are represented scores of similarity obtained from alignment and comparison of 49 sHD nucleotide sequences including 13 HDV-1 sequences, 7 HDV-2, 7 HDV-3, 6 HDV-4, 6 HDV-5, 4 HDV-6, 3 HDV-7, and 3 HDV-8. Below the oblique line are represented scores of similarity obtained from alignment and comparison of 44 complete nucleotide sequences including 13 HDV-1 sequences, 7 HDV-2, 4 HDV-3, 6 HDV-4, 6 HDV-5, 3 HDV-6, 2 HDV-7, and 3 HDV-8. Gray cells show the similarities within each genotype.

Figure 2

Maximum likelihood trees inferred from hepatitis delta virus (HDV) nucleotide sequences. Left panel: Maximum-likelihood phylogram obtained from the small hepatitis delta antigen dataset. Right panel: Maximum-likelihood phylogram obtained from the full-length HDV genome dataset. Bootstrap values (10³ replicates) obtained for neighbor-joining and maximum parsimony are indicated above the branches; posterior probabilities (inferred from 5×10³ trees generated from MrBayes application) are indicated below the branches. Asterisks indicate HDV sequences characterized in this study. Scale is in percent expected substitution per position. The accession numbers of the sequences used were AF209859, AF209859; Cagliari, X85253; China, X77627; dFr45, AX741164; dFr47, AX741149; dFr48, AX741164; dFr73, AX741154; dFr644, AX741169; dFr910, AX741159; dFr1843, AJ583885; dFr2005 (Guinea-Bissau), AM183331; dFr2020, AJ583887; dFr2072 (Senegal), AM183330; dFr2139 (Central African Republic), AM183332; dFr2158 (Cameroon), AM183333; dFr2600 (Togo), AM183326; dFr2627 (Nigeria), AM183329; dFr2703 (Senegal), AM183328; dFr2736 (Côte d'Ivoire), AM183327; Ethiopia, U81989; HDV-Iran, AY633627; Italy, X04451; Japan, X60193; L215, AB088679; Lebanon, M84917; Miyako, AF309420; Miyako-36, AB118845; Miyako-37, AB118846; Nagasaki-2, AB118849; Nauru, M58629; Peru-1, L22063; Somalia, U81988; Taiwan, M92448; Taiwan-3, U19598; Taiwan-Tw-2b, AF018077; Tokyo, AB118847; TW2476, AF104264; TW2667, AF104263; US-1, D01075; US-2, L22066; Vnzd8349, AB037948; Vnzd8375, AB037947; Vnzd8624, AB037949; Yakut-26, AJ309879; and Yakut-62, AJ309880.