FIG. 2.

Phylogenetic tree of the second variable region of RSV group A genotypes and subtypes. The prototype strain USA/Long/56 was used as the outgroup in the analysis. Reference sequences describing the eight different genotypes were retrieved from GenBank and included in the tree. The tree was constructed using the neighbor-joining algorithm with 1,000 replicates through PHYLIP. Subtypes are shown in boldface. The genotypes are indicated by the brackets to the right of the figure. Only bootstrap values greater than 70% are displayed at the branch nodes. The scale bar indicates the number of nucleotide substitutions per site.