Comparison of Tuberculin Activity in the Interferon-gamma Assay for the Diagnosis of Bovine Tuberculosis

Authors: SCHILLER, IRENE - Prionics Ag; SCHRODER, B - Prionics Ag; VORDERMEIER, H - Veterinary Laboratories Agency (VLA); Waters, Wade; Palmer, Mitchell; Thacker, Tyler; WHELAN, ADAM - Veterinary Laboratories Agency (VLA); HARDEGGER, ROLAND - Prionics Ag; MARG-HAUFE, BEATRICE - Prionics Ag; RAEBER, ALEX - Prionics Ag; OESCH, BRUNO - Prionics Ag

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/25/2009
Publication Date: 8/25/2009
Citation: Schiller, I., Schroder, B., Vordermeier, H.M., Waters, W.R., Palmer, M.V., Thacker, T.C., Whelan, A., Hardegger, R., Marg-Haufe, B., Raeber, A., Oesch, B. 2009. Comparison of Tuberculin Activity in the Interferon-gamma Assay for the Diagnosis of Bovine Tuberculosis [abstract].

Interpretive Summary:

Technical Abstract: Cattle infected with bovine tuberculosis still represent a serious regulatory and health concern in a variety of countries. Early diagnosis using the in vitro interferon gamma (IFN-gamma) assay has been applied for more than a decade. Briefly, IFN-gamma responses in whole blood cultures stimulated with purified protein derivatives (PPDs) from Mycobacterium bovis (PPD-B) or M. avium (PPD-A) are quantitated. The production of a higher amount of IFN-gamma in cultures stimulated with PPD-B in comparison to PPD-A is indicative of an M. bovis infection. In the present study, different sources and concentrations of PPDs were compared with regard to diagnostic reliability in experimentally- and naturally-infected animals. Significant differences (P < 0.05) between sources and concentrations of PPD for stimulation were detected, indicating the need for standardization of PPDs used in the IFN-gamma assay. Additionally, we propose a tool named Relative Potency 30 (RP30) that allows rapid comparison of batches and sources of PPDs.