Bartonella /bär′tənel″ə/ [Alberto Barton, Peruvian bacteriologist, 1871–1950] , a genus of small gram-negative flagellated pleomorphic coccobacilli, some of which are opportunistic pathogens. Members of the genus infect red blood cells and the epithelial cells of the lymph nodes, liver, and spleen. They are transmitted at night by the bite of a sandfly of the genus Phlebotomus. Three species are considered important in human disease. B. bacilliformis causes bartonellosis. Because of its distinctive appearance, it is easily identified on microscopic examination of a smear of blood stained with Wright’s stain. B. henselae is the causative agent of cat-scratch fever and bacillary angiomatosis. B. quintana causes trench fever and may cause peliosis of the liver.
