Open AccessAssessment of Mycobacterium tuberculosis OmpATb as a Novel Antigen for the Diagnosis of Bovine Tuberculosis
Author(s) -
Irene Schiller,
H. M. Vordermeier,
W. Ray Waters,
M. V. Palmer,
Tyler C. Thacker,
Adam O. Whelan,
Roland Hardegger,
Beatrice Marg-Haufe,
Alex J. Raeber,
Bruno Oesch
Publication year - 2009
Publication title -
clinical and vaccine immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.649
H-Index - 77
eISSN - 1556-6811
pISSN - 1556-679X
DOI - 10.1128/cvi.00151-09
Subject(s) - bovine tuberculosis , esat 6 , mycobacterium bovis , antigen , tuberculosis , mycobacterium tuberculosis , virology , biology , mycobacterium tuberculosis complex , tuberculin , immunology , microbiology and biotechnology , medicine , pathology
In the search for better tools to control bovine tuberculosis, the development of diagnostic tests with improved specificity and sensitivity has a high priority. We chose to search for novel immunodiagnostic reagents. In this study, Rv0899 (outer membrane protein A ofMycobacterium tuberculosis [OmpATb]) was evaluated as a stimulation antigen in a gamma interferon (IFN-γ) release assay to diagnose bovine tuberculosis. OmpATb induced IFN-γ responses in cattle experimentally infected withM. bovis as early and as persistently as ESAT-6 and CFP-10, the current lead diagnostic antigens. In naturally infected cattle, OmpATb stimulated IFN-γ production in 22 of 26 animals (85%). Importantly, OmpATb detected a portion ofM. bovis -infected cattle which did not respond to ESAT-6 and CFP-10 (five of six cattle). The combined diagnostic sensitivity of OmpATb, ESAT-6, and CFP-10 for a preselected group consisting of naturally infected cattle with an overrepresentation of ESAT-6/CFP-10 nonresponders was 96% (25 of 26 animals). The specificity of OmpATb for uninfected cattle was 100% (27 cattle were tested; 12 of them gave false-positive results with tuberculins). In summary, our results indicate that OmpATb has the potential to enhance the sensitivity of previously described diagnostic tests based on ESAT-6 and CFP-10 and that the combined use of OmpATb, ESAT-6, CFP-10, and other proteins may achieve at least equal sensitivity to that obtained with purified protein derivative, but at a higher specificity. Further studies evaluating the diagnostic performance of OmpATb in combination with other proteins are ongoing.