Genetic analysis of the VP4/VP2 coding region in human rhinovirus species C in patients with acute respiratory infection in Japan

Detailed genetic analysis was carried out of the VP4/VP2 coding region in human rhinovirus species C (HRV-C) strains detected in patients with acute respiratory infection in Japan. Phylogenetic trees were constructed by the neighbour-joining (NJ) and maximum-likelihood (ML) methods. The NJ phylogenetic tree assigned 11 genotypes to the present strains, whilst the ML tree showed that the strains diversified sometime in the early 1870 s. Moreover, the pairwise distance among the present strains was relatively long, and the rate of molecular evolution of the coding region was rapid (3.07 × 10(-3) substitutions per site per year). The results suggest that the present HRV-C strains have a wide genetic divergence and a unique evolutionary timescale.