Bartonella is a genus of Gram negative facultative intracellular bacteria
Bartonella species are transmitted to humans and other mammals (which are its main reservoirs) by vectors such as ticks, fleas, sand flies, and mosquitoes.
after infection they colonize endothelial cells and every 5 days some are released into the circulation to infects RBCs where they multiple
homeless IVDUs are at particular risk of infection
several other species may infect humans and may also cause endocarditis or septicaemia
infection is usually self-limiting in immune competent people in whom antibiotic Rx is of unproven benefit
infection in immunocompromised persons usually requires antibiotic Rx with macrolides, trimethoprim-sulfamethoxazole, gentamicin, ciprofloxacin, or rifampin;
Bartonella henselae
this bacteria is present in the saliva of some kittens (some believe it may be from flea faeces which contaminate scratches) which enters the human via a scratch causing cat scratch disease, or on the open eye - in which case a granulomatous conjunctivitis with preauricular LNs (Parinaud's syndrome) may occur.
it has been shown to induce apoptosis in endothelial cells via a protein
in July 2020, it was shown to also induce angiogenesis in endothelial cells via a protein which they named Bartonella angiogenic factor A (BafA) acting on the endothelial cell's VEGF receptor and which is the 1st known vascular endothelial growth factor (VEGF) like protein found to be produced by bacteria1)