Bartonella
Bartonella is a genus of Gram-negative bacteria. It is the only genus in the family Bartonellaceae.Facultative intracellular parasites, Bartonella species can infect healthy people, but are considered especially important as opportunistic pathogens.Bartonella species are transmitted by vectors such as ticks, fleas, sand flies, and mosquitoes. At least eight Bartonella species or subspecies are known to infect humans.
Bartonella henselae is the organism responsible for cat scratch disease.
Bartonella species have been infecting humans for thousands of years, as demonstrated by Bartonella quintana DNA in a 4000-year-old tooth. The genus is named for Alberto Leonardo Barton Thompson (1871–October 26, 1950), a Peruvian scientist born in Argentina.
The currently accepted model explaining the infection cycle holds that the transmitting vectors are blood-sucking arthropods and the reservoir hosts are mammals. Immediately after infection, the bacteria colonize a primary niche, the endothelial cells. Every five days, some of the Bartonella bacteria in the endothelial cells are released into the blood stream, where they infect erythrocytes. The bacteria then invade a phagosomal membrane inside the erythrocytes, where they multiply until they reach a critical population density. At this point, they simply wait until they are taken up with the erythrocytes by a blood-sucking arthropod.
...
Wikipedia