Serial passage of an attenuated Anaplasma marginale in splenectomized calves.
D000709:Anaplasma / Q000472:pathogenicity*; D000712:Anaplasmosis / Q000276:immunology; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology; D008297:Male; D014774:Virulence