A new type of hepatitis C virus in patients in Thailand

391

285

A method is described for identifying different genotypes of hepatitis C virus (HCV) by restriction endonuclease cleavage of sequences amplified by PCR from the 5' non-coding region. Using the enzymes HaeIII-RsaI and HinfI-MvaI, followed by cleavage with BstU1 or ScrFI, it was possible to identify and distinguish HCV genotypes la, lb, 2a, 2b, 3a, 3b, 4, 5 and 6. The method was used to investigate the prevalence of these genotypes in 723 blood donors in 15 countries, the largest survey to date, and one which covered a wide range of geographical regions (Europe, America, Africa and Asia). These results, combined with a review of the existing literature, indicate the existence of several distinct regional patterns of HCV genotype distribution, and provide the framework for future detailed epidemiological investigations of HCV transmission.

Section: Far-east and South-east Asiasupporting

confidence: 87%

Survey of major genotypes and subtypes of hepatitis C virus using RFLP of sequences amplified from the 5' non-coding region

Davidson

Simmonds²,

Ferguson³

et al. 1995

391

285

“…Based on sequence similarity in the entire genome and within parts thereof, HCV isolates are classified into genotypes I, II, III, IV, V and V! (Mori et al, 1992;Okamoto et al, 1992bOkamoto et al, , d, 1993. Another nomenclature for the classification of HCV is proposed which defines three major types, 1, 2 and 3, with each type being divided into two subtypes, a and b (Chan et al, 1992; The nucleotide sequence data reported in this paper have been deposited in the DDBJ, GenBank and EMBL databases under the following accession numbers: the 5'-terminal 1504 to 1505 nucleotides and the 3'-terminal 1141 to 1154 nucleotides for the NE137 isolate (genotype VI/3b) nos.…”

mentioning

confidence: 99%

“…Genotypes V/3a and VI/3b were proposed originally because of the sequence divergence within a part of the NS5 region (Mori et al, 1992). Fig.…”

mentioning

confidence: 99%

Hepatitis C virus variants from Nepal with novel genotypes and their classification into the third major group

Tokita

Okamoto

Sakamoto

et al. 1994

104

Five isolates of hepatitis C virus (HCV) RNA from patients with chronic liver disease in Nepal were not classifiable into the known genotypes I/la, II/lb, II1/2a, IV/2b or V/3a using PCR with type-specific primers deduced from the HCV core gene. Their nucleotide sequences were determined for the 5'-terminal 1.5 kilobases and 3'-terminal 1.2 kilobases, covering 30 % of the entire genome, and compared with each other and with reported sequences of HCV isolates of various genotypes. They were more similar to a reported HCV isolate (NZL1) of genotype V/3a (in 81.6 to 84.1% of their nucleotides and 85"7 to 88.7% of the deduced amino acid sequence) compared with the genotypes I/la to IV/2b (in 69.3 to 74.7% and 72'3 to 77.4%, respectively). Hence they were considered to be variants of the third major group (group 3). The five HCV isolates shared 81.3 to 85.2% of nucleotide sequence and 85.4 to 89.3 % of deduced amino acid sequence. Thus they were substantially different from each other. One of them was classified as genotype Vl/3b due to an 88-2 % similarity in nucleotide sequence to that of the reported HCV isolates of this genotype, whereas the remaining four were classified into provisional genotypes 3c, 3d, 3e and 3f. These HCV variants have evolved and remained in Nepal, and have not been observed in the other areas of the world.

“…Like other RNA viruses, HCV genomes have shown considerable sequence variation between individual HCV isolates. More than ten different HCV genotypes have so far been identified world-wide (Okamoto et al, 1992;Mori et al, 1992;Simmonds et al, 1993;Tokita et al, 1994;Bukh et al, 1994). Identification of these HCV genotypes is based mainly on the nucleotide sequence diversity and phylogenetic analysis of a specific portion of the HCV genome, i.e.…”

mentioning

confidence: 99%

“…We previously identified two HCV genotypes designated HCV-V (3a) and HCV-VI (3b) (Mori et al, 1992). In this study, to further clarify HCV genotypes, we examined another 24 C-type hepatitis specimens from Thailand by using RT-nested PCR and sequence analysis of the PCR products.…”

mentioning

confidence: 99%

Novel genotypes of hepatitis C virus in Thailand

Sugiyama¹,

Kato²,

Nakazawa³

et al. 1995

We examined 24 C-type hepatitis specimens from Thailand and detected hepatitis C virus (HCV) RNA in all of them by RT-nested PCR for a portion of the HCV 5' non-coding (5' NC) region and a portion of the HCV core region. However, we failed to detect HCV RNA in 11 specimens by RT-nested PCR for a portion in the non-structural protein 5 (NSS) region that has been used commonly for HCV genotyping. We designed a new primer set for a separate portion of the NS5 region. Using this primer set, we succeeded in amplifying this portion in all 24 specimens. Two novel HCV genotypes, tentatively designated HCV-VII and HCV-VIII, were identified by sequencing these amplified regions. Our newly designed primers for RT-nested PCR may be useful for diagnosing infection as well as for genotyping unidentified HCV genomes.