Phylogeny of Brucella calculated using highly conserved ribosomal associated loci. Shown is the single optimization alignment tree based on rplV, tuf-1, tuf-2, and 23S rrn sequences from 28 taxa consisting of the 21 Brucella strains (see Table 1), which included the 18 classical Brucella reference strains and three marine Brucella, and seven outgroups of known genomic sequences. Branch lengths (mean number of differences per residue along each branch) are given as well as bootstrap values (percentage of bootstrap support based on 100 replicates). Legionella pneumophila subspecies Pneumophila strain Philadelphia [GenBank:NC_002942] was used to root the tree. Other bacterial outgroups include: Acinetobacter species ADP1 [GenBank:NC_005966], Caulobacter crescentus CB15 [GenBank:NC_002696], Leptospira interrogans serovar Copenhagen strain Fiocruz L1-130 [GenBank:NC_005823], Mesorhizobium loti MAFF303099 [GenBank:BA000012], Agrobacterium tumefaciens C58 circular [GenBank:NC_003062] and linear chromosomes [GenBank:NC_003063], and Xylella fastidosa 9a5c [GenBank:NC_002488].