Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/25/2006
Publication Date: 6/25/2006
Citation: Harrington, N.P., Prescott, J.F., Waters, W.R., Lyashchenko, K.P., Surujballi, O.P. 2006. Serological Responses of cervids (Cervus elaphus) experimental infected with Mycobacterium bovis: Potential for serodiagnostics [abstract]. In: Proceedings of 4th International Veterinary Vaccines and Diagnostics Conference, June 25-29, 2006, Oslo, Norway. 2006 CDROM.
Technical Abstract: Despite intensive test and slaughter programs, bovine tuberculosis has persisted or remains enzootic in many developed countries. A major reason for this, and one of the greatest threats to any control program of domestic animals, is the infection of wildlife maintenance hosts. They are difficult to control and can, therefore, re-introduce infection to livestock. North American Cervidae including white-tailed deer (Odocoileus virginianus) and elk (Cervus elaphus) have emerged as wildlife reservoirs of Mycobacterium bovis infection of cattle. Methods to detect Mycobacterium bovis infection of wildlife species with improved sensitivity, specificity, and reproducibility are required. Serological tests are appealing because they are rapid and inexpensive, the animals are handled only once, and immediate processing of the sample is not required. To date, however, serological assays have lacked sufficient sensitivity to be used as a single assay. There is a need, therefore, to identify antigens of diagnostic utility that can be used to improve sensitivity without jeopardizing specificity. In this study, we characterized antibody responses of red deer/elk (Cervus elaphus) hybrids experimentally infected with M. bovis. Sequential serum samples were collected and three immunoassays (immunoblot, enzyme-linked immunosorbent assay (ELISA), and multi-antigen print immunoassay (MAPIA)) to a variety of crude and recombinant antigens were used to analyze the developing humoral response. Upon infection, specific bands of reactivity to M. bovis whole cell sonicate were detected by immunoblot and lipoarabinomannan-specific immunoglobulin as early as 56 days post-inoculation. Serum reactivity to twelve native and recombinant antigens coated on nitrocellulose was tested by MAPIA. All M. bovis-infected deer developed responses with one or more of the antigens. Nine of ten deer (90%) had responses to the MPB83 protein and eight of ten (80%) developed responses to the fusion protein Acr1/MPB83. Other proteins identified as major seroreactive antigens included ESAT-6, CFP-10 and MPB70 with less commonly recognized antigens being 38-kDa, MPB59, and MPB64 proteins. Antibody responses were boosted by the injection of purified protein derivative for intradermal tuberculin skin testing. Although the immunodominant response of infected deer was to the MPB83 protein, there was a significant animal-to-animal variation of antigen recognition patterns. These results suggest that a small number of selected antigens hold promise for use in a sensitive serodiagnostic test for the detection of tuberculoisis in cervids.