Experimental Transmission of Sarcocystis from Icterid Birds to Sparrows and Canaries by Sporocysts from the Opossum

Abstract

Cowbirds (Molothrus ater) and grackles (Cassidix mexicanus) infected with muscle cysts of Sarcocystis were fed to opposums (Didelphis virginiana) and fecal sporocysts from the latter were given to sparrows (Passer domesticus, Family Ploceidae), canaries (Serinus canarius, Family Fringillidae) and ducks (Anas platyrhynchos, Family Anatidae). Asexual parasites were found in the endothelium of sparrows and canaries but not in ducks. When birds were kept 10 weeks or more after infection, muscle cysts were found grossly and microscopically in the majority of sparrows, and in 1 canary, but not in ducks. Muscle zoites were found in digests of all sparrows and canaries but not in that of ducks. Metrocytes and forms dividing by endodyogeny also were found in the digest. Thus, avian Sarcocystis was transmitted experimentally from 2 genera of 1 family (Icteridae) to 2 different families of passerine intermediate hosts by sporocysts from the definitive host. This is the broadest intermediate host spectrum known for a species of Sarcocystis. Transmission of Sarcocystis by obligatory alternation of hosts for the sexual and asexual stages has been accomplished with a number of predator-prey combinations. The most intensively studied have been the cycles between the canine and feline predators and wild and domestic meat animals (Levine, 1977). Transmission of rabbit Sarcocystis by cats (Fayer and Kradel, 1977; Crum and Prestwood, 1977) and murine Sarcocystis by cats (Ruiz and Frenkel, 1976), owls (Cerna, 1976; Munday, 1977) and snakes (Rzepczyk, 1974) also has been described. We recently were able to transmit avian Sarcocystis from grackles and cowbirds (the intermediate hosts) to opossums, which served as definitive hosts (Duszynski and Box, 1978). Although previously Sarcocystis was thought to be rather host specific, parasitizing one genus of intermediate host (Levine, 1977), this report describes the successful transmission of the muscle parasite from Icteridae (cowbirds and grackles) to Ploceidae sparrows) and Fringillidae (canaries) by sporocysts from opossums. MATERIALS AND METHODS Experimental intermediate hosts Adult sparrows (Passer domesticus) were captured in a Havahart trap on the University of Texas Medical Branch campus in March before

Description of Sarcocystis campestris sp. n. (Protozoa: Sarcocystidae): a parasite of the badger Taxidea taxus with experimental transmission to the Richardson's ground squirrel, Spermophilus richardsonii

“…Sarcocystis debonei utilizes three familes (four genera) of birds as intermediate hosts (Box and Duszynski 1978). Similarly, a species of Sarcocystis from Cervidae can also develop in two genera of Bovidae (Erber 1980), and S. odocoileocanis of Cervidae will also develop in two genera of Bovidae (Crum et al 198 1).…”

A novelSarcocystis-associated encephalitis and myositis in racing pigeons

“…Sarcocystis falcatula uses miscellaneous avian species as intermediate hosts and the North American opossum (Didelphis virginiana) as the definitive host (Box & Duszynski, 1978;Box et al, 1984). The brown headed cowbird (Moluthrus ater) has recently been identified as the intermediate host of Sarcocystis neurona (Mansfield et al, 2008), the definitive host of which is the opossum (D. virginiana and Didelphis albiventris) (Dubey et al, 2001a).…”

Prevalence of Sarcocystis species sporocysts in Northern Virginia opossums (Didelphis virginiana)

“…The North American opossum (Didelphis virginiana) is considered the natural reservoir and definitive host for at least three pathogenic species of Sarcocystis: S. falcatula of birds (Box and Duszynski 1978;Box et al 1984), S. neurona of horses (Dubey et al 1991;Fenger et al 1997;, and S. speeri with an unknown intermediate host Dubey and Lindsay 1999). Therefore, understanding the epidemiology of S. neurona and other Sarcocystis spp in wild opossums will aid our understanding of exposure for horses.…”