Development of a simple, sensitive, rapid test which discriminates BCG-vaccinated fromMycobacterium bovis-infected cattle

• Published in: Vaccine 2008-10, Vol.26 (43), p.5470
• Main Authors: Sopp, P, Coad, M, Hewinson, G, Howard, CJ, Cheallaigh, C Ni, Keane, J, Harris, J, Hope, JC
• Format: Article
• Language: English
• Subjects: Blood; Cattle; Immunization; Tuberculosis; Vaccines
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2008.07.059

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 discriminateMycobacterium bovis-infected from BCG-vaccinated animals. Herein, we demonstrate that the detection of secreted IFN-γ following short term culture (4h) of whole blood with purified protein derived fromM. bovis(PPD-B) allows such discrimination. This reflects, in part, the differential kinetics of IFN-γ secretion in infected compared to vaccinated cattle. This is the first study to demonstrate that accurate, rapid distinction of BCG-vaccinated fromM. bovis-infected cattle can be achieved in a short time period without the need for production ofM. bovis-specific antigens, complex antigen mixtures or extensive laboratory procedures. We were also able to detect PPD-specific IFN-γ 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.