Taxonomy of genus Hepacivirus : application of palindromic nucleotide substitutions for the determination of genotypes of human hepatitis C virus species

The palindromic nucleotide substitutions (PNS) in the 5'-untranslated region (UTR) of Pestivirus RNA have been described as a new, simple and practical method for genotyping. Given the genetic relatedness between Pestivirus and hepatitis C virus species, the application of the method was investigated preliminarily on 180 isolates, including reference strains. The keys for hepatitis C virus identification have been determined at the genus, species, genotype and subtype levels. Secondary structure nucleotide substitutions were characteristics to the genus included in a complex stem-loop structure composed of 112-115 nucleotides. Due to the worldwide importance of hepatitis C virus, and the difficulties encountered in the control of the disease, it is, therefore, important to understand the genetic aspects of the virus. The application of the PNS method might represent an additional useful tool for determining the genetic variations among hepatitis C virus strains. The identification of viral types or subtypes based on genetic changes should improve our understanding of hepatitis C virus and might provide markers for biological differences, such as virulence, and improve understanding of the evolution of the virus.