title: In vitro lymphocyte transformation as a herd survey method for bovine paratuberculosis.
abstract: The lymphocyte-transformation (LT) test was evaluated for its potential application as a field test for bovine paratuberculosis. Using a whole blood technique, samples from 3 consecutive collection periods were subjected to 3 mycobacterial antigens and to phytohemagglutinin. The results obtained from LT were compared with conventional serologic and cultural methods. A positive LT response to johnin purified-protein derivative (PPD) or avian PPD (or both) was noted in 40% to 60% of the animals tested. The complement-fixation test yielded 4% to 6.7% positive results, the immunodiffusion test between 1.2% and 1.4%, and the direct fecal culture between 2.4% and 6%. The mean of the stimulation indices of all positively responding animals was highest with johnin PPD. Specific stimulation to mammalian PPD occurred between 2.4% and 6% of the animals. The efficacy of the LT test for determining the incidence of infection with Mycobacterium paratuberculosis is discussed.
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis*; D003168:Complement Fixation Tests; D005260:Female; D005779:Immunodiffusion; D008213:Lymphocyte Activation; D009161:Mycobacterium / Q000276:immunology; D009162:Mycobacterium avium / Q000276:immunology; D009163:Mycobacterium bovis / Q000276:immunology; D010283:Paratuberculosis / Q000175:diagnosis*; D014373:Tuberculin
chemical_list: D000942:Antigens, Bacterial; D014373:Tuberculin