| Title |
Serodiagnosis of M. paratuberculosis infection using lipoarabinomannan and antigen D in enzyme linked immunosorbent assays: comparison with agar gel immunodiffusion in sheep and after pre-absorption of sera with M. phlei in cattle |
| Author(s) |
Sugden EA,
Michaelides A,
Bosse J.
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| Institution(s) |
Agriculture Canada, Animal Diseases Research Institute, NEPEAN, P.O. Box 11300, Station H, Nepean, Ontario, Canada, K2H 8P9.
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| Source |
Third International Colloquium on Paratuberculosis
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| Section |
1:
Laboratory Diagnosis
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| Abstract |
This study sought further improvements in the serodiagnosis of paratuberculosis. Comparing paratuberculosis infected sheep with non-infected sheep the agar gel immunodiffusion test for paratuberculosis using antigen D (D-AGID) was superior to enzyme linked immunosorbent assays using lipoarabinomannan antigen (LAM-ELISA) and protein antigen D (D-ELISA), although used in conjunction with D-AGID the LAM-ELISA showed an increase in specificity. For paratuberculosis infected sheep the LAM-ELISA test showed good agreement with D-AGID (kappa = 0.74), but there was less agreement for sheep submitted for routine serodiagnosis for which the infection status was unknown (kappa = 0.19). A large number of LAM-ELISA positive routine sheep sera were not D-AGID positive, and one-third of the D-AGID positive routine sera were missed by LAM-ELISA. Pre-absorption of sera from paratuberculosis-infected and paratuberculosis-free cattle with M. phlei resulted in an increase in LAM-ELISA specificity from 90.7% to 97.3% at a sensitivity of 70.8% relative to LAM-ELISA conducted without pre-absorption.
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