Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 17, 2003
Publication Date: N/A
Technical Abstract: The development of antigen based diagnostic tests requires that species-specific antigens be identified. However, for Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis), no such antigens have been described. This is due, at least in part, to the high genomic similarity between M. paratuberculosis and M. avium subsp. avium (M. avium). Despite this high similarity, we have identified at least 21 predicted coding sequences that are present only in M. paratuberculosis. Nucleotide sequences representing each of these unique predicted coding regions were amplified and cloned into an E. coli expression vector. Ninety percent of expressed mycobacterial proteins were successfully purified under denaturing conditions. Purified recombinant M. paratuberculosis proteins were used in immunoblotting studies with sera from rabbits and mice immunized with whole cell preparations of M. paratuberculosis. Only five of the 21 gene products were detected by all sera tested. Immunoblot analysis with sera from naturally infected and control cattle shows that these same M. paratuberculosis proteins are recognized in the context of infection. Collectively, these studies have used a comparative genomic approach to rapidly identify novel M. paratuberculosis antigens that are not present in any other mycobacteria.