DIFFERENTIATION OF SARCOCYSTIS-NEURONA FROM 8 RELATED COCCIDIA BY RANDOM AMPLIFIED POLYMORPHIC DNA ASSAY

Four isolates of Sarcocystis neurona from horses with equine protozoal myeloencephalitis and eight species of coccidia from the genera Sarco cystis, Toxoplasma or Eimeria were differentiated using the random amp lified polymorphic DNA assay. A single, common, 550-bp DNA fragment wa s amplified from the DNA of each S. neurona isolate using a 16-nucleot ide primer. Crosshybridization analyses among S. neurona isolates show ed that DNA fragments had at least partial sequence homology. The prim er generated several DNA fragments, including a 550-bp DNA fragment, f rom S. cruzi, Eimeria falciformis, E. neischulzi, E. ahsata and E. bov is. DNA hybridization analyses indicated no sequence homology between these fragments and the 550-bp DNA fragment generated from S. neurona. The S. neurona 550-bp DNA fragment also did not hybridize with genomi c blots of various other coccidia. These results suggest that the S. n eurona DNA fragment may be exploited as a species-specific probe for t his parasite.