There is considerable confusion concerning the species of Sarcocystis in South American camelids (SAC). Several species names have been used; however, proper descriptions are lacking. In the present paper, we redescribe the macroscopic sarcocyst forming Sarcocystis aucheniae and describe and propose a new name, Sarcocystis masoni for the microscopic sarcocyst forming species. Muscles samples were obtained from llamas (Lama glama) and guanacos (Lama guanicoe) from Argentina and from alpacas (Vicugna pacos) and llamas from Peru. Individual sarcocysts were processed by optical and electron microscopy, and molecular studies. Microscopic sarcocysts of S. masoni were up to 800 µm long and 35-95 µm wide, the sarcocyst wall was 2·5-3·5 µm thick, and had conical to cylindrical villar protrusions (vp) with several microtubules. Each vp had 11 or more rows of knob-like projections. Seven 18S rRNA gene sequences obtained from sarcocysts revealed 95-96% identity with other Sarcocystis spp. sequences reported in the GenBank. Sarcocysts of S. aucheniae were macroscopic, up to 1·2 cm long and surrounded by a dense and laminar 50 µm thick secondary cyst wall. The sarcocyst wall was up to 10 µm thick, and had branched vp, appearing like cauliflower. Comparison of the 11 sequences obtained from individual macroscopic cysts evidenced a 98-99% of sequence homology with other S. aucheniae sequences. In conclusion, 2 morphologically and molecularly different Sarcocystis species, S. masoni (microscopic cysts) and S. aucheniae (macroscopic cysts), were identified affecting different SAC from Argentina and Peru.

Sera from 186 sheep, 83 cattle, and 103 water buffaloes from Punjab, India, were evaluated for antibodies to Toxoplasma gondii using a commercial ELISA kit. This study was planned using a 2-stage random sampling procedure and sampling software 'survey toolbox.' In the first step, villages were selected randomly from a sampling frame of all the villages of Punjab, followed by selection of owners and animals in the second step. Antibodies to T. gondii were found in 7 of 186 sheep, 2 of 83 cattle, and 3 of 103 buffaloes. Results indicate a low prevalence of T. gondii in ruminants tested.

The protozoan parasite Sarcocystis falcatula is an important cause of clinical disease in several avian intermediate hosts. The host range of S. falcatula is wide and numerous outbreaks of acute sarcocystosis have been reported in passerine and psittacine birds in captivity in the Americas. Previous diagnosis was performed by serologic methods, light and/or electron microscopic examinations with limited molecular confirmation. Here, we report histological and molecular diagnosis of acute, fatal S. falcatula infections in rainbow lorikeets (Trichoglossus moluccanus) at the Philadelphia Zoo. Pulmonary sarcocystosis was suspected antemortem in 3 lorikeets (3-5 yr old); these birds died despite anti-protozoal therapy. The predominant lesion was pneumonia associated with S. falcatula-like schizonts in pulmonary vascular endothelium. The multilocus PCR-DNA sequencing (18S rDNA, 28S rDNA, ITS-1, and cox1) of frozen lung tissue confirmed S. falcatula infections in all 3 birds. Our results and previous studies suggest that acute pulmonary form of sarcocystosis is a major contributor of death to old world psittacine birds.

Cattle (Bos taurus) are intermediate hosts for three named species of Sarcocystis, S. cruzi, S. hirsuta, and S. hominis. Recently, a fourth species was identified and named S. sinensis. However, S. sinensis originally named a species of Sarcocystis in water buffalo (Bubalus bubalis) in China. Based on unverifiable evidence, it was suggested that the same parasite infects cattle. In addition, S. sinensis was recently declared as nomen nudum because its naming violated the rules of International Code of Zoological Nomenclature. Thus, the fourth species using cattle as an intermediate host does not have a valid name. Here, we propose a new name, Sarcocystis rommeli for the S. sinensis-like parasite from cattle in Argentina, and differentiate it ultrastructurally from S. hominis sarcocysts from experimentally infected cattle. Sarcocystis rommeli sarcocysts were microscopic with a 5-μm-thick wall with slender villar protrusions (Vp); the Vp were up to 5 μm long, up to 0.5 μm wide, and of uneven thickness, often bent at an angle. The ground substance layer (Gs) was up to 0.8 μm thick and smooth. Vesicular structures were seen at the base of the Vp. The bradyzoites were 10-12 μm long. Sarcocystis hominis sarcocysts had Vp that were often upright, up to 7.5 μm long, and up to 1.8 μm wide; the Gs was up to 2 μm thick and without vesicles. Its sarcocyst wall was up to 5.6 μm thick, the vp were bent at an angle, up to 5.8 μm long, the Gs was up to 2 μm thick, but without vesicles seen in S. rommeli. Beef containing sarcocysts of S. rommeli was not orally infectious for two human volunteers and a red fox (Vulpes vulpes). The Sarcocystis described here is molecularly different from S. cruzi, S. hirsuta, and S. hominis based on 18S rRNA and cox1 gene sequences.

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The muscles of herbivores commonly harbor sarcocysts of parasites belonging to species in the genus Sarcocystis, but such muscle parasites are rare in carnivores. Here, we report Sarcocystis arctica-like sarcocysts in muscles of Arctic foxes (Vulpes lagopus) from Alaska, USA, for the first time. The tongues of 56 foxes were examined for Sarcocystis infection using several methods. Sarcocystis bradyzoites were detected in pepsin digests of 13 (23.2%), and sarcocysts were found in histological sections stained with hematoxylin and eosin (HE) of 9 (16.0%). By light microscopy, sarcocysts were up to 4 mm long and up to 245 μm wide. In HE-stained sections, the sarcocyst wall appeared smooth and up to 1.5 μm thick without visible protrusions. By transmission electron microscopy, the sarcocyst wall had a wavy parasitophorous vacuolar membrane (pvm) folded as pleomorphic villar protrusions (vp), sometimes with anastomoses of villar tips. The vp and the ground substance (gs) layer were smooth and without microtubules. The gs was up to 2.0 μm thick. The total width of the wall including vp and the gs was up to 4.0 μm. The vp were up to 3.0 μm long and most closely resembled "type 9c." All sarcocysts were mature and contained numerous 8.1 × 2.1 μm sized bradyzoites. Molecular characterization (at 18S rDNA, 28S rDNA, ITS-1, and cox1) showed the highest affinity for S. arctica of the Arctic fox (V. lagopus) from Norway. In the present investigation, we provide evidence that sarcocysts are common in tongues of Alaskan Arctic foxes suggesting that these carnivores are serving as intermediate hosts, and we also provide ultrastructure of S. arctica from the Arctic fox for the first time.

SummaryThere is considerable confusion concerning Sarcocystis species in equids. Little is known of Sarcocystis infections in donkeys (Equus asinus). Here we describe the structure of Sarcocystis bertrami from the donkey by light and transmission electron microscopy (LM, TEM). Nineteen sarcocysts from the tongue of a donkey from Egypt were studied both by LM and TEM. By LM, all sarcocysts had variably shaped and sized projections on the cyst walls, giving it a thin walled to thick walled appearance, depending on individual cyst and plane of section. By TEM, sarcocysts walls had villar protrusions (vp) of type 11. The sarcocyst wall had conical to slender vp, up to 6 μm long and 1μm wide; the vp were folded over the cyst wall. The total thickness of the sarcocyst wall with ground substance layer (gs) was 1-3 μm. The vp had microtubules that originated deeper in the gs and continued up to the tip. The apical part of the vp had electron dense granules. The microtubules (mt) were configured into three types: a tuft of electron dense mt extending the entire length of the vp with a tuft of medium electron dense mt appearing in parallel, and fine mt present only in the villar tips. The gs was mainly smooth with few indistinct granules. The gs was mainly smooth with few indistinct granules. All sarcocysts were mature and contained metrocytes and bradyzoites. Bradyzoites were approximately 11-15 x 2-3 μm in size with typical organelles.

Chickens are considered important in the epidemiology of Toxoplasma gondii. Chicken hearts (n = 1185) obtained from grocery stores were tested for T. gondii infection. Antibodies to T. gondii were assayed in fluid removed from the heart cavity using the modified agglutination test (MAT) at 1:5, 1:25, and 1:100 dilutions. MAT antibodies were detected in 222 hearts at 1:5 dilution and 8 hearts at 1:25 dilution, but none were positive at 1:100 dilution. Seropositive (n = 230, 19.4%) chicken hearts were bioassayed in mice and seronegative (n = 157) chickens were bioassayed in cats. Viable T. gondii was not isolated from any hearts by bioassays in mice. The 2 cats fed 60 and 97 hearts did not excrete T. gondii oocysts. The results indicate a low prevalence of viable T. gondii in chickens from grocery stores. Molecular typing of 23 archived T. gondii strains isolated from free-range chickens from Ohio and Massachusetts using the 10 PCR-RFLP markers including SAG1, SAG2 (5'-3'SAG2 and altSAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico revealed that seven were ToxoDB PCR-RFLP genotype #1, 11 were genotype #2, one was genotype #3, three were genotype #170, and one was mixed genotype. These results indicate that the clonal genotypes #1 (type II), #2 (type III), and #3 (type II variant) are common in free-range chickens.