Characterization of Sarcocystis from four species of hawks from Georgia, USA

During 2001 to 2004, 4 species of hawks (Buteo and Accipiter spp.) from Georgia were surveyed for Sarcocystis spp. infections by examining intestinal sections. In total, 159 of 238 (66.8%) hawks examined were infected with Sarcocystis spp. Samples from 10 birds were characterized by sequence analysis of a portion of the 18S rRNA gene (783 base pairs). Only 3 of the 10 sequences from the hawks were identical; the remainder differed by at least 1 nucleotide. Phylogenetic analysis failed to resolve the position of the hawk Sarcocystis species, but they were closely related several Sarcocystis species from raptors, rodents, and Sarcocystis neurona. The high genetic diversity of Sarcocystis suggests that more than 1 species infects these 4 hawk species; however, additional molecular or experimental work will be required to determine the speciation and diversity of parasites infecting these avian hosts. In addition to assisting with determining species richness of Sarcocystis in raptors, molecular analysis should be useful in the identification of potential intermediate hosts.