Answer
A genus of Rickettsiales bacteria, Ehrlichia, was named in honor of Paul Ehrlich, a German bacteriologist who discovered the antimicrobial properties of salvarsan, the first arsenic-based chemotherapeutic agent used to treat syphilis. Ehrlichia species are intracellular bacteria that infect leukocytes, causing ehrlichiosis, a disease that can range from mild to severe and can even be fatal.