ARS | Publication request: Evaluation of Ethanol Extracted Surface Antigens of Mycobacterium bovis for Diagnosis of Bovine Tuberculosis in Livestock Cattle and Wild Deer

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 23, 2010
Publication Date: May 23, 2010
Citation: Eda, S., Bannantine, J.P., Wadhwa, A., Eda, K., Scott, M.C., Mackintosh, C., Waters, W.R. 2010. Evaluation of Ethanol Extracted Surface Antigens of Mycobacterium bovis for Diagnosis of Bovine Tuberculosis in Livestock Cattle and Wild Deer [abstract].

Technical Abstract: Background: Bovine tuberculosis (TB), caused by Mycobacterium bovis, is a zoonotic disease resulting in chronic granulomatous lymphadenitis, particularly in the lungs and lung-associated lymph nodes. Although bovine TB has been nearly eradicated in many developed countries, the disease persists primarily due to wildlife reservoirs and importation of infected animals from countries with endemic bovine TB. Current diagnostic methods include postmortem histopathological examination, skin test, an interferon-gamma assay, and newly emerging antibody detection tests. Antibody detection tests offer rapid and field-applied platforms. The objective of this study is to identify new diagnostic antigens for diagnosis of bovine TB. Previous studies have demonstrated that an ethanol extract of M. paratuberculosis (paraTB) contains strongly reactive M. paraTB-specific antigens. Based on this finding, we evaluated ethanol extracted molecules of M. bovis as candidate antigens for diagnosis of bovine TB in cattle and red deer. Methods: M. bovis antigens were extracted by treating the bacteria with 80% ethanol for one minute. Reactivity with serum samples obtained from M. bovis-infected and uninfected animals was evaluated by enzyme-linked immunosorbent assay. Also, the ethanol extract was further characterized by Western blotting and thin layer chromatography. Results: Ethanol extracted molecules of M. bovis reacted with serum samples obtained from calves experimentally infected with M. bovis. Also, the extract reacted with sera of deer naturally infected with M. bovis. Although sera of M. paraTB-infected deer also reacted with the M. bovis extract, M. paraTB-infected samples could be differentiated from M. bovis-infected samples by comparisons to reactivity with an M. paraTB ethanol extract. M. bovis-specific lipids and MPB83 protein were detected in the M. bovis ethanol extract. Conclusion: The M. bovis ethanol extract contained M. bovis-specific molecules and reacted with serum samples from M. bovis-infected animals. The antigens in the extract may form a basis for the development of a new serological test for bovine TB.