title: Resistance to anaplasmosis after elimination of latent Anaplasma marginale infections.
abstract: Ten 30-month-old cattle (group 2) were inoculated with Anaplasma marginale 6 months after the latent A marginale infection was eliminated by oral chlortetracycline therapy. In addition, 4 cattle (group 1) with no record of infection and 4 cattle (group 3) of equivalent age previously vaccinated with a killed antigen were similarly inoculated. Moderate to severe clinical signs of acute anaplasmosis occurred in the group 1 (previously uninfected) cattle, whereas only 1 of the chlortetracycline-treated cattle (group 2) and none of the vaccinated cattle (group 3) had clinical evidence of disease.
mesh_terms: D000712:Anaplasmosis / Q000188:drug therapy / Q000276:immunology*; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy / Q000276:immunology*; D002751:Chlortetracycline / Q000627:therapeutic use; D003168:Complement Fixation Tests; D005260:Female; D008297:Male
chemical_list: D002751:Chlortetracycline