|Torioni DE Echaid, S. - WASHINGTON STATE UNIV|
|Palmer, G - WASHINGTON STATE UNIV|
|Mcguire, T - WASHINGTON STATE UNIV|
|Mcelwain, T - WASHINGTON STATE UNIV|
Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 12, 1996
Publication Date: N/A
Interpretive Summary: Anaplasmosis is a persistent infection in cattle and represents an export problem for producers within the United States. An accurate test for detection of cattle persistently infected with anaplasmosis was not available. We found through studying the bovine immune response to the organisms of anaplasmosis that one of the organism¿s proteins was consistently recognized by infected cattle, sheep and goats. This protein called MSP5 was isolated, characterized and tested for use in diagnosis. We found this protein (MSP5) was consistently recognized by infected cattle. A patent has been filed and the technology licensed by Veterinary Medical Research and Development (VMRD), a biomedical company. This assay will assure that the true anaplasmosis status of cattle is determined for the purposes of export from the United States.
Technical Abstract: A competitive inhibition ELISA (cELISA) for the detection of bovine anti-MSP5 antibodies was developed by using purified recombinant MSP5 fusion protein and mAb ANAF16C1. The specificity of the recombinant- MSP5 cELISA within North America was established by using 261 serum samples from cattle in the regions of Hawaii and Northern Ontario where anaplasmosis is not endemic and from cattle proven by splenectomy or subinoculation of whole blood into susceptible splenectomized recipients to be uninfected. The maximum percent inhibition by these sera was 18%. Sera known to be positive were obtained from 35 cattle either experimentally inoculated with infected erythrocytes or exposed to infected Dermacentor andersoni ticks. Thirty-four of the 35 serum samples inhibited mAb ANAF16C1 binding by >25%. During acute infection, the MSP5 cELISA detected antibodies prior to or concomitantly with the appearance of rickettsiae in erythrocytes. Antibodies were detectable in sera from persistently infected cattle inoculated as long as 6 years previously.