Bartonella henselae

Bartonella henselae, formerly Rochalimæa henselae, is a bacterium that is the causative agent of cat-scratch disease (bartonellosis).

Bartonella henselae is a member of the genus Bartonella, one of the most common types of bacteria in the world. The specific name henselae honors Diane Marie Hensel (b. 1953), a clinical microbiology technologist at University of Oklahoma Health Sciences Center, who collected numerous strains and samples of the infective agent during an outbreak in Oklahoma in 1985. It is a facultative intracellular microbe that targets red blood cells. One study showed it invaded the mature blood cells of humans. It infects the host cell by sticking to it using trimeric autotransporter adhesins. In the United States, about 20,000 cases are diagnosed each year, most under 15 years old. Most often, it is transmitted by scratches or bites from kittens.