Phylogenetic distribution of virulence genes.

<p>Each functional category of virulence-related genes is represented as a vertical bar. Positive values denote association of a particular functional category with pathogenic species of a certain taxonomic group, while negative values with non-pathogenic species. Taxons are grouped according to phylogenetic relationships. In graph legend: ABC: ABC transporters, TCS&CH: two-component systems and chemotaxis, MOT&FLA: motility and flagellar assembly, TOX: toxins, SS: secretion systems, LPS: LPS biosynthesis.