Figure 1.
S. aureus genetic diversity. (A) Genome-wide distribution of absent ORFs among the 36 S. aureus strains studied. Red and black denote presence or absence of ORFs, respectively. RDs are marked by black arrows and were numbered arbitrarily, because the genome sequence of strain COL is not complete. (B) Dendrogram showing estimates of genomic relationships of the 36 strains constructed by complete linkage hierarchical cluster analysis. Strains were grouped with the cluster program on the basis of the presence or absence of ORFs with RDs treated as single loci, and the output was displayed with the computer program treeview. Phylogenetic lineage and ET of each strain are presented. Red text signifies MRSA strains. The scale represents the value of the Pearson correlation coefficient at each node. For a pairwise comparison, a coefficient of 1 would denote absolute identity, and zero would indicate complete independence.