Sequencing and Phylogenetic Study of Partial NS3 Gene of Iranian GB Virus C/Hepatitis G Virus (HGV) Originated From Hemodialysis Patients in Tehran

BACKGROUND Hepatitis viruses are one of the most important concerns in the patients on hemodialysis who are at high risk for blood-borne infections. GB virus C (GBV-C)/hepatitis G virus (HGV) is positive-stranded RNA virus with global distribution, which codes structural and nonstructural proteins (such as NS3). OBJECTIVES Review on literature about Iranian HGV isolates showed that there was no report on sequencing and phylogenetic characteristics of NS3 gene and therefore, this study attempted to answers these challenges. MATERIALS AND METHODS Briefly, steps followed were as follows: preparation of nucleic acids from three Iranian hemodialysis HGV-positive samples and RNA extraction; reverse transcriptase-PCR (RT-PCR) for amplification of NS3 gene and gel electrophoresis; sequencing and analyzing sequencing data; NCBI Registering; blasting and alignment of sequences; and finally constructing the phylogenetic tree. RESULTS Nucleotide BLAST results emphasized that most similar sequences to Ir NS3 sequences were those from Europe (Spain, Germany, and the United Kingdom) and the United states and IR sequences were located with five leaves in a branch. In addition, homology of Ir sequences showed96.4% (between IR1 and IR2), 94.9% identity (between IR1 and IR3), and 96.5% identity (between IR2 and IR3).Furthermore, highly variation and significance differences in NS3 between GBC isolates from geographical regions and some little changes in IR sequences were seen. Finally, phylogenetic tree revealed that NS3 genotype of Iranian isolates was probably similar to European countries and USA. CONCLUSIONS Overall, results of present study were consistent with the data reported earlier base on 5' NTR in Iranian isolates and revealed genotype IR2 is major genotype in Iranian HGV-positive patient. It means there are higher similarities between Iranian and Europe-USA in HGV NS3 gene.