The Opossum (\u3ci\u3eDidelphis virginiana\u3c/i\u3e) as a Host for \u3ci\u3eSarcocystis debonei\u3c/i\u3e from Cowbirds (\u3ci\u3eMolothrus ater\u3c/i\u3e) and Grackles (\u3ci\u3eCassidix mexicanus\u3c/i\u3e, \u3ci\u3eQuiscalus quiscula\u3c/i\u3e)

Sarcocystis-infected muscles from ducks, cowbirds, and grackles were fed to cats, opossums, rats, and a dog. Only the opossum (Didelphis virginiana) was a suitable definitive host. All opossums that were fed Sarcocystis-infected cowbirds (Molothrus ater) and grackles (Cassidix mexicanus and Quiscalus quiscula) passed sporocysts in their feces. Opossums that ate the cowbirds had prepatent periods of 5 and 10 days and remained patent for at least 105 days. Opossums that ate the grackles became patent on day 10 after the infective meal and remained patent for over 90 (Quiscalus) and 105 (Cassidix) days. A single opossum fed infected muscle from a pintail duck (Anas acuta) passed sporocysts in the feces from days 13 through 18 after infection. No sporocysts were passed by opossums fed infected muscle from the green-winged teal (Anas carolinensis) and shoveller (Spatula clypeata). Sporocysts of duck, cowbird, and grackle origin were structurally similar. Mean dimensions of sporocysts were: duck-origin, 11.2 by 8.2 μm; cowbird-origin, 11.4 by 7.8 μm; Cassidix-origin, 11.2 by 7.8 μm; and Quiscalus-origin, 11.6 by 7.7 μm. We designate the sporocysts of cowbird and grackle origin as Sarcocystis debonei Vogelsang, 1929 (Syn. Isospora boughtoni Volk, 1938)

The Opossum (\u3ci\u3eDidelphis virginiana\u3c/i\u3e) as a Host for \u3ci\u3eSarcocystis debonei\u3c/i\u3e from Cowbirds (\u3ci\u3eMolothrus ater\u3c/i\u3e) and Grackles (\u3ci\u3eCassidix mexicanus\u3c/i\u3e, \u3ci\u3eQuiscalus quiscula\u3c/i\u3e)

Sarcocystis-infected muscles from ducks, cowbirds, and grackles were fed to cats, opossums, rats, and a dog. Only the opossum (Didelphis virginiana) was a suitable definitive host. All opossums that were fed Sarcocystis-infected cowbirds (Molothrus ater) and grackles (Cassidix mexicanus and Quiscalus quiscula) passed sporocysts in their feces. Opossums that ate the cowbirds had prepatent periods of 5 and 10 days and remained patent for at least 105 days. Opossums that ate the grackles became patent on day 10 after the infective meal and remained patent for over 90 (Quiscalus) and 105 (Cassidix) days. A single opossum fed infected muscle from a pintail duck (Anas acuta) passed sporocysts in the feces from days 13 through 18 after infection. No sporocysts were passed by opossums fed infected muscle from the green-winged teal (Anas carolinensis) and shoveller (Spatula clypeata). Sporocysts of duck, cowbird, and grackle origin were structurally similar. Mean dimensions of sporocysts were: duck-origin, 11.2 by 8.2 μm; cowbird-origin, 11.4 by 7.8 μm; Cassidix-origin, 11.2 by 7.8 μm; and Quiscalus-origin, 11.6 by 7.7 μm. We designate the sporocysts of cowbird and grackle origin as Sarcocystis debonei Vogelsang, 1929 (Syn. Isospora boughtoni Volk, 1938)

Electronic decision support systems at point of care: trusting the deus ex machina

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Justin J Beilby, Andre J Duszynski, Anne Wilson and Deborah A Turnbul

A New \u3ci\u3eEimeria\u3c/i\u3e Species (Apicomplexa: Eimeriidae) Infecting \u3ci\u3eOnychomys\u3c/i\u3e Species (Rodentia: Muridae) in New Mexico and Arizona

Fecal samples from 3 species of Onychomys (Rodentia: Muridae) captured in New Mexico and Arizona were examined for coccidia. Six of the 59 (10%) were infected with a new species of Eimeria. Sporulated oocysts (n = 105) of this new species are subspheroidal, 17.4 × 16.1 (14-21 × 13-19) μm, with ellipsoidal sporocysts 10.4 × 5.7 (9-12 × 5-8) μm. This species occurred in 3 of 24 (13%) Onychomys arenicola, 2 of 31 (6%) Onychomys leucogaster from New Mexico, and 1 of 4 (25%) Onychomys torridus from Arizona. Isolates recovered from O. leucogaster and O. torridus were inoculated into O. leucogaster (n = 5) and produced infections with a prepatent period of 7 days and a patent period of 7-23 days

A New \u3ci\u3eEimeria\u3c/i\u3e Species (Apicomplexa: Eimeriidae) Infecting \u3ci\u3eOnychomys\u3c/i\u3e Species (Rodentia: Muridae) in New Mexico and Arizona

Fecal samples from 3 species of Onychomys (Rodentia: Muridae) captured in New Mexico and Arizona were examined for coccidia. Six of the 59 (10%) were infected with a new species of Eimeria. Sporulated oocysts (n = 105) of this new species are subspheroidal, 17.4 × 16.1 (14-21 × 13-19) μm, with ellipsoidal sporocysts 10.4 × 5.7 (9-12 × 5-8) μm. This species occurred in 3 of 24 (13%) Onychomys arenicola, 2 of 31 (6%) Onychomys leucogaster from New Mexico, and 1 of 4 (25%) Onychomys torridus from Arizona. Isolates recovered from O. leucogaster and O. torridus were inoculated into O. leucogaster (n = 5) and produced infections with a prepatent period of 7 days and a patent period of 7-23 days

\u3ci\u3eSarcocystis\u3c/i\u3e of Passerine Birds: Sexual Stages in the Opossum (\u3ci\u3eDidelphis virginiana\u3c/i\u3e)

Sexual stages of a Sarcocystis of passerine birds were demonstrated by feeding muscle cysts from cowbirds (Molothrus ater) and grackles (Cassidix mexicanus) to opossums (Didelphis virginiana). Opossums were examined at necropsy at 36 h, 13.5 days, and 29.5 days post-inoculation (PI). Large numbers of macro- and microgamonts were present in the small intestine 36 h PI, while only sporocysts and oocysts were present 13 days or more PI. Microgamonts in different stages of development were in the intestinal epithelium above the nucleus and macrogamonts were at the base of the epithelial cells or in the lamina propria. Oocysts and sporocysts were in the core of the villus, beneath the basement membrane. Descriptions are given of the sexual stages as they appear in sections and smears

Experimental Transmission of \u3ci\u3eSarcocystis\u3c/i\u3e from Icterid Birds to Sparrows and Canaries by Sporocysts from the Opossum

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