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United States Department of Agriculture

Agricultural Research Service


item Granstrom David
item Macpherson J M
item Gajadhar Alvin A
item Dubey, Jitender
item Tramontin Robert
item Stamper Shelby

Submitted to: Molecular and Cellular Probes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/7/1994
Publication Date: N/A
Citation: N/A

Interpretive Summary: Equine protozoal myeloencephelits (EPM) is a fatal disease of horses. The life cycle and source of infection for EPM are unknown. EPM affects the young and old horses and the disease is confined to the Americas. Most cases of EPM are diagnosed after death. The etiologic agent of EPM, Sarcocystis neurona, was recently grown in cell culture. Scientists at the Agricultural Research Center and the University of Kentucky have isolated a fragment (portion) of DNA from culture derived Sarcocystis neurona. The results will be useful for the development of a DNA based test for the diagnosis of EPM in live horses.

Technical Abstract: Four isolates of Sarcocystis neurona, obtained from horses with equine protozoal myeloencephalitis and eight species of coccidia from the genera Sarcocystis, Toxoplasma, and Eimeria were differentiated using the random amplified polymorphic DNA assay. A single, common 550 bp DNA fragment was amplified from the DNA of each S. neurona isolate using a 16-nucleotide primer. Cross hybridization analyses among S. neurona isolates showed that DNA fragments had at least partial sequence homology. The primer generated several DNA fragments, including a 550 bp DNA fragments, from S. cruzi, Eimeria falciformis, E. neischulzi, E. ahsata and E. bovis. DNA hybridization analyses indicated no sequence homology between these fragments and the 550 DNA fragment generated from S. neurona. The S. neurona 550 bp DNA fragment also did not hybridize with genomic blots of various other coccidia. These results suggest that the S. neurona DNA fragment may be exploited as a species-specific probe for this parasite.

Last Modified: 06/27/2017
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