FIG. 1.

Unrooted neighbor-joining tree based on partial rpoB gene sequences showing the phylogenetic relationships among 29 species of the genus Staphylococcus. The numbers are the estimated confidence levels, expressed as percentages, for the positions of the branches, determined by bootstrap analysis; only bootstraps values of >70% are indicated. The scale bar indicates the evolutionary distance between sequences, determined by measuring the lengths of the horizontal lines connecting two organisms (0.01 substitution/site).