Blood culture and stimulation conditions for the diagnosis of tuberculosis in cervids by the Cervigam assay.
Mitogen- and antigen-induced interferon-gamma (IFN-gamma) responses of peripheral blood leucocytes from cervids were evaluated by a commercial whole-blood assay. The assay was applied to Mycobacterium bovis-infected white-tailed deer and reindeer, M bovis BCG-vaccinated white-tailed deer and elk, and unvaccinated, uninfected white-tailed deer, fallow deer, elk and reindeer. The responses of the M bovis-infected white-tailed deer to pokeweed mitogen (PWM) varied with time and between individuals. The responses of the M bovis-infected reindeer to PWM and M bovis purified protein derivative (PPD) were positively associated. Samples from tuberculosis-free captive herds in various parts of the USA were also evaluated. Four per cent of fallow deer, 20 per cent of elk, 44 per cent of white-tailed deer, and 91 per cent of reindeer had responses to PWM exceeding 0.25 Delta optical density, that is, PWM stimulation minus no stimulation. The specificity of the responses to M bovis PPD and a Mycobacterium tuberculosis complex-specific antigen rESAT-6:CFP-10, excluding animals not responding to PWM, ranged from 78 per cent to 100 per cent and was dependent upon the species and the positive response cut-off value. The results show that the commercial assay is valid for the detection of TB in reindeer; however, further development of the assay will be required before it is used in surveillance programmes for white-tailed deer, fallow deer, and elk.
Waters
W R
WR
Tuberculosis Research Project, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA 50010, USA.
Palmer
M V
MV
Thacker
T C
TC
Orloski
K
K
Nol
P
P
Harrington
N P
NP
Olsen
S C
SC
Nonnecke
B J
BJ
D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology*; D001500:BCG Vaccine / Q000276:immunology*; D003208:Concanavalin A / Q000494:pharmacology; D003670:Deer / Q000276:immunology / Q000382:microbiology; D005260:Female; D007371:Interferon-gamma / Q000096:biosynthesis*; D007962:Leukocytes; D008213:Lymphocyte Activation; D008297:Male; D009163:Mycobacterium bovis / Q000276:immunology*; D010835:Phytohemagglutinins / Q000494:pharmacology; D011043:Pokeweed Mitogens / Q000494:pharmacology; D012053:Reindeer / Q000276:immunology / Q000382:microbiology; D014376:Tuberculosis / Q000097:blood / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D014611:Vaccination / Q000662:veterinary
D000942:Antigens, Bacterial; D001500:BCG Vaccine; D010835:Phytohemagglutinins; D011043:Pokeweed Mitogens; D003208:Concanavalin A; D007371:Interferon-gamma