Members of the genus Bartonella are facultative intracellular bacteria belonging to the alpha 2 subgroup of the class Proteobacteria and are phylogenetically closely related to Brucella species. Until 1993, only three diseases were known to be caused by Bartonella species: Carrion's disease (Bartonella bacilliformis), trench fever (Bartonella quintana), and cat scratch disease (CSD; Bartonella henselae). The genus now comprises B. bacilliformis, species of the former genera Rochalimea and Grahamella, and additional, recently described species . In mammals, each Bartonella species is highly adapted to its reservoir host; the bacteria can persist in the bloodstream of the host as the result of intraerythrocytic parasitism. Intraerythrocytic localization of B. henselae has been demonstrated in cat erythrocytes and B. bacilliformis bacilli have been observed within erythrocytes during the acute phase of Carrion's disease (Oroya fever). Bartonellae also have a tropism for endothelial cells, and intracellular B. henselae can be identified in endothelial cells infected in vitro, although intraendothelial cell bacilli have not been identified in vivo.
Antimicrobial Agents and Chemotherapy
Antimicrob Agents Chemother. 2004 Jun;48(6):1921-33