Bartonella spp are members of the α-proteobacteria group
that includes the genera Rickettsia, Ehrlichia, Brucella, and
the plant pathogen Agrobacterium tumefaciens. They are
fastidious bacteria that occur in the blood of man and
mammals. Disease is usually transmitted by hematophagous
insects, such as sandflies (Lutzomyia spp), fleas, and lice, but
can also be transmitted by animal scratches and bites.1