Impact of Corynebacterium pseudotuberculosis infection on serologic surveillance for Johne's disease in goats

摘要

In goats and sheep, false-positive results due to antibody produced by Corynebacterium pseudotuberculosis (C. PsTB) infection are reported to occur on serologic assays for M. a. paratuberculosis {M. ptb.). This issue of compromised specificity was evaluated by testing 557 adult goats from 8 Midwestern goat herds. Assays for M. ptb. infection include radiometric fecal culture and two commercially available Johne's disease ELiSAs: one USDA-licensed for cattle only (ELISA-1) and one USDA-licensed for cattle, sheep and goats (ELISA-2). A case of M. ptb. infection was defined as a fecal culture-positive goat from a herd With known clinical cases of Johne's disease. A hemolysin inhibition assay (HI) was used to detect C. PsTB antibody. A case of C. PsTB infection was defined as a goat with an HI titer >= 1:8 from a herd with confirmed cases of C. PsTB infection.