Molecular identification of Sarcocystis halieti n. sp., Sarcocystis lari and Sarcocystis truncata in the intestine of a white-tailed sea eagle(Haliaeetus albicilla) in Norway.

Abstract An emaciated white-tailed sea eagle( Haliaeetus albicilla) from Western Norway was found and nursed briefly before it died. The necropsy revealed that the principal cause of death was an inflammation and occlusion of the bile ducts. A secondary finding was the presence in the intestinal mucosa of numerous sporulated Sarcocystisoocysts measuring 21.8–22.8 × 16.0–17.0 μm. The aim of this study was to identify these oocysts to species level using molecular methods. Genomic DNA was extracted from 10 mucosal scrapings containing oocysts and subjected to PCR amplification and sequencing of four DNA regions: the 18S and 28S rRNA genes, the ITS1 region and the cox1 gene. DNA of three previously known Sarcocystisspp. was identified, but only two of these, Sarcocystishalieti n. sp. and Sarcocystis lari, both employing sea birds as intermediate hosts, were considered to have used the sea eagleas a definitive host and to have formed oocysts in its intestine. The third species found, Sarcocystistruncata , employs red deer as intermediate hostsand seems to use felids as definitive hosts based on its phylogenetic position and prevalence. The sea eaglehad probably recently ingested portions of one of the latter hosts (red deer or cat/lynx) containing stages (sarcocysts/oocysts) and thus DNA of S. truncata . The species S. halieti and S. laricould only be unambiguously separated from their most closely related congeners on the basis of their ITS1 sequences. This is the first report of Sarcocystisoocysts in sea eaglesand the first identification to species level of Sarcocystisoocysts in any type of eagle. The sea eaglealso acted as intermediate hostof an unidentified Sarcocystisspp. as evidenced by the finding of six thin-walled sarcocysts in a histological section of cardiac muscle.