Performance of a Johne's Disease Enzyme-Linked Immunosorbent Assay Adapted for Milk Samples from Goats

Abstract

Antibody detection–based tests for paratuberculosis offer speed and economy, 2 diagnostic test attributes important to animal industries with narrow profit margins. Application of such tests to individual milk samples instead of serum samples can further improve testing efficiency and decrease testing cost. Accuracy of a commercial bovine paratuberculosis enzyme-linked immunosorbent assay (ELISA) adapted for use on goat serum and milk samples was determined. Fecal, blood, and milk samples were collected from 159 goats belonging to 2 Wisconsin goat herds with a prior history of paratuberculosis and 1 herd of 50 goats from a paratuberculosis-free Wisconsin herd. Fecal samples were cultured using the modified BACTEC 12B media. Sera were tested according to the manufacturer's instructions for bovine samples. Milk samples were centrifuged and mixed with the ELISA kit's Mycobacterium phlei–containing diluent at a ratio of 1:2. Using fecal culture as the “gold standard,” the sensitivity of the ELISA on goat serum was 64% and the sensitivity of the ELISA on goat milk was 48%. The milk ELISA had higher agreement with fecal culture results (kappa = 0.525) than the serum ELISA (kappa = 0.425). ELISA specificity was 100% on both serum and milk. Regression analysis also showed good correlation between serum and milk S/P values ( r2 = 0.67). Although less sensitive, the ELISA on goat milk samples appears to offer a useful, low-cost alternative for detection of goats with paratuberculosis that have progressed to the stage of shedding M. paratuberculosis in their feces.

Seroprevalence of Mycobacterium avium subspecies paratuberculosis in Korean Black Goats (Capra hircus aegagrus)

“…All samples were tested using a commercial ELISA kit, as recommended by the manufacturer (HerdChek ® Mycobacterium paratuberculosis Test Kits, IDEXX Laboratories, ME, U.S.A.). Analytical procedures for ELISA in this study were identical to those outlined earlier for goats [9]. The absorbance reading in all ELISA plate wells was measured at 650 nm by an ELISA reader (Power Wave XS; Bio-Tek, VT, U.S.A.).…”

Recent Approaches in Diagnosis and Control of Mycobacterial Infections with Special Reference to Mycobacterium Avium Subspecies

“…Due to the differences in days after parturition less correlation has been found in certain cases between serum and milk ELISA. In order to detect anti-MAP antibodies, both milk as well as serum ELISA have been found effective (Klausen et al, 2003;Hendrick et al, 2005;Salgado et al, 2005;Duthie et al, 2007).…”

The Johne paradigm: From detection to management to treatment

“…17,18,23 Reports of variability in the sensitivity of the ELISA for the diagnosis of MAP-positive sera for isolates derived from different host species is not surprising since antigen preparation is not standardized. [24][25][26] Although the current challenges discussed here have been plaguing Johne disease researchers for some time, recent events in research conducted by Click et al [26][27][28][29] shed a sense of optimism on a somewhat overwhelming subject. 29 This data shows a direct impact of Dietzia not only on the shedding of MAP bacteria in the feces but also on the disease status of the individual.…”