Immunoglobulin G1 enzyme-linked immunosorbent assay for diagnosis of Johne's Disease in red deer (Cervus elaphus).

Abstract

This study was designed to develop a customized enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of Johne's disease (JD) in farmed deer. Two antigens were selected on the basis of their superior diagnostic readouts: denatured purified protein derivative (PPDj) and undenatured protoplasmic antigen (PpAg). ELISA development was based on the antigen reactivity of the immunoglobulin G1 (IgG1) isotype, which is a highly specific marker for mycobacterial disease seroreactivity in deer. Sensitivity estimates and test parameters were established using 102 Mycobacterium paratuberculosis-infected animals from more than 10 deer herds, and specificity estimates were determined using 508 uninfected animals from 5 known disease-free herds. A receiver-operated characteristic analysis determined that at a cut point of 50 ELISA units, there was a specificity of 99.5% and sensitivities of 84.0% with PPDj antigen, 88.0% with PpAg, and 91.0% when the antigens were used serially in a composite test. Estimated sensitivity was further improved using recombinant protein antigens unique for M. paratuberculosis, which identified infected animals that were unreactive to PPDj or PpAg. While 80% of animals that were seropositive in the IgG1 ELISA had detectable histopathology, the assay could also detect animals with subclinical disease. The test was significantly less sensitive (75%) for animals that were culture positive for M. paratuberculosis but with no detectable pathology than for those with pathological evidence of JD (>90%). When the IgG1 ELISA was used annually over a 4-year period in a deer herd with high levels of clinical JD, it eliminated clinical disease, increased production levels, and reduced JD-related mortality.

• Authors: J Frank T Griffin, Evelyn Spittle, Christie R Rodgers, Simon Liggett, Marc Cooper, Douwe Bakker, John P Bannantine
• Journal: Clinical and diagnostic laboratory immunology (Clin Diagn Lab Immunol) Vol. 12 Issue 12 Pg. 1401-9 (Dec 2005) ISSN: 1071-412X [Print] United States
• PMID: 16339063 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Bacterial
• Immunoglobulin G
• Tuberculin

Topics

• Animals
• Antibodies, Bacterial (blood)
• Bacteriological Techniques (methods)
• Deer
• Enzyme-Linked Immunosorbent Assay (methods)
• Immunoglobulin G (isolation & purification)
• Mycobacterium avium subsp. paratuberculosis (immunology)
• Paratuberculosis (diagnosis, immunology)
• Predictive Value of Tests
• ROC Curve
• Sensitivity and Specificity
• Serologic Tests
• Tuberculin