Molecular Identification of Sarcocystis rileyi and Sarcocystis sp. (Closely Related to Sarcocystis wenzeli ) in Intestines of Mustelids from Lithuania.

The genus Sarcocystis is a group of numerous protozoan parasites having a two-host life cycle. Based on laboratory experiments and/or phylogenetic analysis results it was shown that seven Sarcocystis spp. producing sarcocsyts in bird tissues are transmitted via predatory placental mammals. To date the role of small mammals of the family Mustelidae in the distribution of avian Sarcocystis spp. have not been studied. During the current investigation, intestinal mucosa scrapings of 115 mustelids belonging to five species were tested for S. albifronsi, S. anasi , S. rileyi , and S. wenzeli infecting anseriforms and chickens. Microscopically, free sporocysts, sporulating oocysts, and loose oocysts were found in 61 samples (53.0%). Using nested PCR targeting the ITS1 region and sequencing, S . rileyi was confirmed in eight American minks, two European polecats and single European badger. Sarcocystis sp. was identified in one American mink and one European pine marten. Based on the partial ITS1 region this parasite showed that 100% identity to pathogenic Sarcocystis sp. caused a fatal infection in backyard chickens from Brazil. Phylogenetically, the Sarcocystis sp. identified in our study was most closely related to S . wenzeli parasitising domestic fowl ( Gallus domesticus ).