Phylogeny, arthropod vectors and mammalian hosts of the genus Bartonella and the distribution of type IV secretion systems. Left: Phylogenetic tree of the genus Bartonella based on multilocus sequence analysis (MLSA, [116]). Right: summary table of the host specificity and the presence and absence of loci encoding type IV secretion systems in the different Bartonella species. Adapted from Dehio [51].