title: Antibody responses of cervids (Cervus elaphus) following experimental Mycobacterium bovis infection and the implications for immunodiagnosis.
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.
authors.affiliation: Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, Ottawa, Ontario, Canada. harringtonnp@inspection.gc.ca
authors.forename: Noel P
authors.initials: NP
authors.lastname: Harrington
authors.forename: Om P
authors.initials: OP
authors.lastname: Surujballi
authors.forename: John F
authors.initials: JF
authors.lastname: Prescott
authors.forename: J Robert
authors.initials: JR
authors.lastname: Duncan
authors.forename: W Ray
authors.initials: WR
authors.lastname: Waters
authors.forename: Konstantin
authors.initials: K
authors.lastname: Lyashchenko
authors.forename: Rena
authors.initials: R
authors.lastname: Greenwald
mesh_terms: D000818:Animals; D000835:Animals, Wild; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D015151:Immunoblotting; D007159:Immunologic Tests / Q000379:methods; D009163:Mycobacterium bovis / Q000276:immunology*; D012418:Ruminants / Q000276:immunology*; D013997:Time Factors; D014376:Tuberculosis / Q000175:diagnosis / Q000662:veterinary*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial