Study of NS5B gene mutations in hepatitis C virus genotype 1a in Guilan Province

Hepatitis C virus is the main cause of chronic hepatitis, resulting in a thousand deaths every year. NS5B protein is an RNA-dependent RNA polymerase that is encoded by the NS5B gene and involved in virus replication. One of the most effective drugs in the treatment of infections caused by this virus are NS5B protein inhibitors. The emergence of the strains resistant to these drugs is a major obstacle to the success of treatment. The aim of this study was to investigate possible mutations in the NS5B region of hepatitis C virus genotype 1a in Guilan province.   Materials & HCV genomic RNA was extracted from the plasma samples of 225 anti-HCV positive patients and its molecular identification and genotyping was carried out by RT-PCR and product Sequencing. Then, the NS5B gene was amplified in 10 strains with genotype 1a and subsequently sequenced to determine mutations in this region.   Genotypes 3a (53.3%) and 1a (36.9%) were the most abundant genotypes identified in Guilan. According to sequencing results, out of 10 investigated genotype 1a strains, 5 strains showed 7 types of missense mutations in codons Q309, A327, S254, K304, N307, R250, and A334.   Genotype 1a is one of the common genotypes of hepatitis C virus in Guilan. Identifying mutations or polymorphisms associated with resistance in hepatitis C virus can be useful in optimizing the treatment and determining the efficacy of drugs in treating hepatitis C virus.