Development of a simple, sensitive, rapid test which discriminates BCG-vaccinated from Mycobacterium bovis-infected cattle.
Bovine tuberculosis (bTB) is increasing in incidence in the UK. Effective control strategies could involve vaccination; BCG, either alone or in prime-boost strategies, remains the most effective vaccine against bovine tuberculosis. However, BCG vaccination of cattle would require development of diagnostic tests able to accurately discriminate Mycobacterium bovis-infected from BCG-vaccinated animals. Herein, we demonstrate that the detection of secreted IFN-gamma following short term culture (4h) of whole blood with purified protein derived from M. bovis (PPD-B) allows such discrimination. This reflects, in part, the differential kinetics of IFN-gamma secretion in infected compared to vaccinated cattle. This is the first study to demonstrate that accurate, rapid distinction of BCG-vaccinated from M. bovis-infected cattle can be achieved in a short time period without the need for production of M. bovis-specific antigens, complex antigen mixtures or extensive laboratory procedures. We were also able to detect PPD-specific IFN-gamma release during short term culture of blood from a number of humans with active TB indicating that this test may have wider application and is potentially useful for the rapid diagnosis of disease in humans.
Sopp
P
P
Institute for Animal Health, Compton, Newbury, Berkshire RG207NN, United Kingdom.
Coad
M
M
Hewinson
G
G
Howard
C J
CJ
Cheallaigh
C Ni
CN
Keane
J
J
Harris
J
J
Hope
J C
JC
D000818:Animals; D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000235:genetics; D001500:BCG Vaccine / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002417:Cattle; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis / Q000096:biosynthesis; D007700:Kinetics; D009163:Mycobacterium bovis / Q000276:immunology*; D014380:Tuberculosis, Bovine / Q000276:immunology*; D014397:Tuberculosis, Pulmonary / Q000276:immunology; D014611:Vaccination
D000942:Antigens, Bacterial; D001500:BCG Vaccine; D016207:Cytokines; D007371:Interferon-gamma