Sequence variation within a nonstructural region of the hepatitis G virus genome

Abstract

Nine sets of nested PCR primers from a 2.6-kb region of the hepatitis G virus (HGV) genome at nucleotide positions 5829 to 8421 were designed and used to analyze serum specimens obtained from patients with community-acquired non-A, non-B hepatitis who were HGV RNA positive. One set of primers was found to be most efficient in detecting HGV and was subsequently used to test 162 HCV-positive and 11 HCV-negative plasma units obtained from individual paid donors. HGV RNA was detected in 30 (17.3%) plasma units, 2 of which were found among the 11 HCV-negative specimens. A complete set of nine PCR fragments was obtained from two patients with community-acquired acute non-A, non-B hepatitis and from four paid donors. All PCR fragments were sequenced and were shown to have a nucleotide similarity of 85.9 to 92.3% and a derived amino acid similarity of 96.0 to 99.0%. The majority of nucleotide changes occurred in the third position of codons. The HGV nucleotide and protein sequences obtained in this study were compared with HCV sequences. Based on this analysis the 2.6-kb fragment was predicted to encode the C-terminal part of the putative NS4b, the entire NS5a, and almost the complete NS5b proteins. Putative protease cleavage sites separating these proteins were also predicted. In serial specimens obtained from the two HGV-infected patients, no significant variations were found in the HGV nucleotide and derived amino acid sequences over time. The HGV sequences obtained from one patient showed no changes over 6 months, whereas more than 99.0% homology was observed for sequences from the second patient over 2.5 years. Heterogeneity analysis performed on 10 sequences obtained in this study and corresponding regions from 6 known full-size sequences of the HGV genomes demonstrated notable discrete heterogeneity consistent with the existence of HGV genetic groups or types.

Prevalence and genotypes of GB virus C/hepatitis G virus (GBV-C/HGV) and hepatitis C virus among patients infected with human immunodeficiency virus: Evidence of GBV-C/HGV sexual transmission

“…Since we have only analyzed a small segment of the genome, the existence of different GBV-C/HGV genotypes among these 33 Spanish isolates can not be ruled out. Recently, evidence for the existence of GBV-C/ HGV genotypes based on analysis of the entire 5ЈNCR, or longer coding regions, has been reported [Fukushi et al, 1996;Muerhoff et al, 1996Muerhoff et al, , 1997Khudyakov et al, 1997;Okamoto et al, 1997;Smith et al 1997]. In contrast, independent analysis of the E2, NS3, or NS5b region sequences did not identify the existence of GBV-C/HGV genetics groups or types [Muerhoff et al, 1997].…”

“…Analysis of the E2, NS3, or NS5b region sequences did not identify the existence of GBV-C/HGV genetics groups or types [Muerhoff et al, 1997]. However, based on sequence heterogeneity of the 5Ј noncoding region (5ЈNCR), or longer coding regions, at least three different types of GBV-C/HGV variants have been described [Fukushi et al, 1996;Muerhoff et al, , 1997Khudyakov et al, 1997;Okamoto et al, 1997;Smith et al, 1997]. Although infection with certain strains of GBV-C/HGV in patients with fulminant hepatic failure [Heringlake et al, 1996] has not been confirmed, the possibility that strain variation might be related to the pathogenicity of GBV-C/HGV cannot be disregarded.…”

Age-specific prevalence and genetic diversity of GBV-C/hepatitis G virus in Brazil

“…The age-specific GBV-C/HGV RNA seroprevalence was evaluated in 268 individuals without liver disease living in Rio de Janeiro. This was carried out by RTnested PCR using a set of primers designed from the NS5 region and highly efficient for this purpose [Khudyakov et al, 1997]. Except for one eight-year-old child, the youngest individual infected was 15 years old and the curve of prevalence showed a peak at 18% in young adults aged 21-30 years (Table I).…”

Distinct prevalence of antibodies to the E2 protein of GB virus C/hepatitis G virus in different parts of the world

“…GBV-C/HGV RNA was detected by RT-PCR as described elsewhere [Khudyakov, et al 1997;] with few modifications. RNA was extracted from 140 L of serum with a QIAamp viral RNA kit (QUIAGEN, Hilden, Germany) and resuspended in 50 L of H 2 O.…”