Antibody Responses of Cervids (Cervus elaphus) following Experimental Mycobacterium bovis Infection and the Implications for Immunodiagnosis

Authors

• Noel P. Harrington, Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, Ottawa, Ontario, Canada
• Om P. Surujballi, Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, Ottawa, Ontario, Canada
• John F. Prescott, Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
• J. Robert Duncan, Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, Ottawa, Ontario, Canada
• W. Ray Waters, National Animal Disease Center, U.S. Department of Agriculture, Ames, IowaFollow
• Konstantin Lyashchenko, Chembio Diagnostic Systems, Inc., Medford, New York
• Rena Greenwald, Chembio Diagnostic Systems, Inc., Medford, New York

Date of this Version

11-2008

Comments

Published in CLINICAL AND VACCINE IMMUNOLOGY, Nov. 2008, p. 1650–1658.

Abstract

Captive and free-ranging wildlife animals are implicated in the maintenance and transmission of bovine tuberculosis and therefore pose a significant obstacle to eradication of the disease from domestic livestock. The current antemortem diagnostic method, the intradermal tuberculin skin test, is impractical for routine use with many wild animals. Antibody-based assays are particularly attractive because the animals are handled only once and immediate processing of the sample is not required. This report characterizes the antibody responses of red deer-elk hybrids (Cervus elaphus) against Mycobacterium bovis and subsequently evaluates the diagnostic performance of select antigens in a rapid-test format. Sequential serum samples were collected from 10 animals experimentally infected with M. bovis and 5 noninfected animals over a 7-month period postinfection (p.i.). Samples were evaluated by enzyme-linked immunosorbent assays, immunoblot analyses, and multiantigen print immunoassays for seroreactivity to mycobacterial antigens. Although all infected animals produced antibodies to M. bovis protein antigens, there was significant animal-to-animal variation in the kinetics and magnitudes of responses and the antigens recognized. The most frequently recognized antigens included MPB83, ESAT-6, CFP10, and MPB70. Responses to some antigens, such as MPB83, were consistently detected as early as 4 weeks after inoculation, whereas other antigens were detected only much later (>140 days p.i.). Antibody responses were boosted by injection of tuberculin for intradermal tuberculin skin testing. Comparison of single-antigen (fluorescence polarization assay) with multiantigen (CervidTB STAT-PAK) rapid tests demonstrated that a highly sensitive and specific serodiagnostic test for tuberculosis in cervids will require multiple and carefully selected seroreactive antigens covering a broad spectrum of antibody specificities.