Molecular detection of Sarcocystis sp. in a kept under human care black capuchin monkey (Sapajus nigritus., Goldfuss 1809) with necrotizing encephalitis.

A senile male black capuchin monkey (Sapajus nigritus) kept under human care in a Zoo was found dead after 2 weeks presenting signals of weight loss and hyporexia. Histopathological revealed a necrotizing encephalitis. Although it was not observed microscopically, Sarcocystis sp infection was detected in brain tissue from molecular assays. These infections have been rarely described in neotropical primates, particularly associated with tissue lesions.

First molecular detection of Sarcocystis suihominis in a domestic pig of Nigeria.

Sarcocystis are Apicomplexan protozoa with a dixenous life cycle that includes a predator and a prey as definitive and intermediate hosts, respectively. Domestic and wild pigs are intermediate hosts of S. suihominis, with formation of sarcocysts in their muscles, while humans and non-human primates act as final hosts. After ingesting raw or undercooked sarcocyst-infested pork, signs of gastroenteritis including inappetence, nausea, vomiting, and diarrhea may develop in humans. Moreover, excretion of infective forms with human feces leads to dissemination of the parasite in the environment. In this study, macroscopic sarcocysts of white color, oval shape, and a diameter of approximately 3-8 mm were found in the skeletal muscle of a slaughtered domestic pig (Sus scrofa domesticus) destined for human consumption in an abattoir of Makurdi, Benue State, Nigeria. Sarcocyst DNA was used as template to PCR amplify the near-complete length of the 18S rRNA gene and a fragment of the cytochrome c oxidase subunit 1 (cox-1) gene. Amplicons were sequenced and used to construct phylogenetic trees with selected available Sarcocystis spp. sequences. In both cases, the placement of the analyzed sequences with S. suihominis was strongly supported, confirming the species identity of this macroscopic sarcocyst-forming parasite. This constitutes the first molecular identification of S. suihominis in Nigeria and the African continent. Proximity between pigs and humans, and poor sanitary conditions frequently encountered in pig farms of Nigeria might favor the dissemination of this zoonotic parasite, posing a threat to public health.

Gross lesions associated with Sarcocystis miescheriana in a wild boar hunted for human consumption: the importance of trained hunters to ensure animal health surveillance and food safety.

Sarcocystis is a genus of protozoa with a worldwide distribution infecting a wide range of animals, including humans. Wild boars can harbor at least two species of Sarcocystis, that is, the zoonotic Sarcocystis suihominis, using humans as definitive hosts, and Sarcocystis miescheriana, for which wild and domestic canids serve as definitive hosts. In Portugal, hunting holds significant economic and social importance, and wild boars are among the most appreciated hunted species. As the consumption of wild boar meat can expose humans to several foodborne pathogens, the presence of trained hunters can make a difference in ensuring animal health surveillance and food safety. Herein, we report the detection of macroscopic cystic lesions associated with S. miescheriana in a wild boar hunted for human consumption, resulting in carcass condemnation. To the best of the authors' knowledge, the presence of S. miescheriana in wild boar tissues has never been associated with macroscopic pathological alterations before. Although S. miescheriana cannot infect humans, carcasses affected by grossly visible pathological changes must be declared unfit for consumption. Therefore, our finding points out the potential economic damage associated with carcass rejection due to the presence of gross lesions associated with generalized sarcocystosis. Nonetheless, further studies are required to investigate these alterations that currently appear to be occasional findings.

Development of a highly specific LAMP assay for detection of Sarcocystis tenella and Sarcocystis gigantea in sheep.

Sarcocystis infection in sheep has caused significant economic losses in the livestock industry, and the genetic similarity among Sarcocystis species highlights the need for precise diagnostic methods in sheep. This study developed a loop-mediated isothermal amplification (LAMP) method targeting COX-1 and 28S rRNA genes to detect Sarcocystis tenella and Sarcocystis gigantea, respectively. The LAMP method exhibited high specificity, selectively amplifying target DNA sequences without cross-reactivity with closely related protozoa, such as Toxoplasma gondii and Neospora caninum. Detection limits were determined as 3 × 105 copies/L for S. tenella and 6 × 104 copies/L for S. gigantea, enabling sensitive identification of low-level infections. Comparative analysis with conventional PCR on sheep cardiac tissues demonstrated a higher LAMP detection rate (80.0% vs 66.7%). In conclusion, the LAMP method offers superior sensitivity to conventional PCR, allows visual confirmation of results, and provides a rapid diagnostic tool for identifying S. tenella and S. gigantea infection in sheep. However, due to the limitation of sample availability, we were unable to assess all Sarcocystis species that use sheep as intermediate hosts, which warrants further research.

Diversity of Sarcocystis parasites in southeastern Baltic Sea catchment ecosystems.

Currently, research on apicomplexan Sarcocystis parasites is mainly carried out by analyzing animal carcasses. However, environmental studies would not only allow faster detection of possible sources of infection but also avoid the use of animals for investigations. Therefore, in the current study, we aimed to identify tested Sarcocystis species in sediment collected from water bodies located in the southeastern Baltic countries. A total of 99 sediment samples were collected during the summer from different types of water bodies in Estonia, Latvia, Lithuania, and Poland. Species-specific nested PCR targeting cox1 gene was used for the detection of selected Sarcocystis species (S. cruzi, S. bovifelis, S. hirsuta, S. arieticanis, S. tenella, S. capracanis, S. miescheriana, and S. bertrami) infecting livestock. The results showed a statistically lower (p < 0.05) occurrence of Sarcocystis parasites in Estonia (50%) compared to three countries, where the detection rate of Sarcocystis spp. DNA was remarkably higher, ranging from 88 to 100%. Among Sarcocystis species tested, S. cruzi (83.8%) and S. arieticanis (55.6%) using cattle and sheep as their intermediate hosts were most commonly identified. The detection rates of some of the analyzed Sarcocystis species were significantly different in southeastern Baltic countries. It is discussed that the detection rates of certain Sarcocystis species depend not only on the number of animals per 1 km2 but also on various ecological factors and farming practices that differ in the amount of contact domestic animals have with predators and the potential for animals to become infected through natural water or food sources.

Microscopic detection and molecular characterization of Sarcocystis miescheriana in wild boars (Sus scrofa): first report from Greece.

The genus Sarcocystis includes protozoan parasites with an indirect life cycle. Sarcocystis spp. can infect various animal species and humans, causing sarcocystosis, a parasitosis of economic importance and zoonotic concern. Wild boars can act as intermediate hosts for Sarcocystis miescheriana and the zoonotic Sarcocystis suihominis that infects humans by consumption of raw or undercooked infected swine meat. In the present study, the diaphragmatic muscle tissue of 123 wild boars hunted in Greece was examined to determine the frequency of Sarcocystis spp. The samples were examined by tissue compression and molecular techniques. Under light microscopy, 34 out of 123 (27.6%) wild boars tested positive for Sarcocystis spp., while a higher infection prevalence (75%) was revealed by multiplex PCR performed in 100 of the samples. The partial mtDNA cox1 gene (~ 1100 bp) of 20 samples tested positive for S. miescheriana by multiplex PCR was amplified and sequenced. Sarcocystis miescheriana was identified as the only species involved in these infections. This is the first study on the prevalence of Sarcocystis spp. in wild animals in Greece. Further, large-scale surveys are needed to assess the prevalence and species of this parasite in Greece and to design efficient control and preventive measures in a One Health perspective.

First report of Sarcocystis falcatula in naturally infected Razorbill auks (Alca torda) collected in Tunisian Mediterranean Sea shores.

Sarcocystis spp. are apicomplexan cyst-forming parasites that can infect numerous vertebrates, including birds. Sarcosporidiosis infection was investigated in three muscles (breast, right and left thigh muscle) and one organ (heart) of four Razorbill auks (Alca torda) stranded between November and December 2022 on the shores of the Mediterranean Sea in Nabeul and Bizerte governorates, Northern Tunisia. Two of the four tested A. torda were PCR positive for 18S rRNA Sarcocystis spp. gene. Among the examined 16 muscles/organs, only one breast and one right thigh were Sarcocystis spp. PCR-positive (12.5% ± 8.3, 2/16). Our results showed a relatively high molecular prevalence of Sarcocystis spp. in Razorbill auks (A. torda). Sarcocystis spp. sequence described in the present study (GenBank number: OR516818) showed 99.56-100% identity to Sarcocystis falcatula. In conclusion, our results confirmed the infection of Razorbill auks (A. torda) by S. falcatula. Further research is needed on different migratory seabirds' species in order to identify other Sarcocystis species.

Sarcocystis cruzi (Hasselmann, 1923) Wenyon, 1926: redescription, molecular characterization and deposition of life cycle stages specimens in the Smithsonian Museum.

Currently, 7 named Sarcocystis species infect cattle: Sarcocystis hirsuta, S. cruzi, S. hominis, S. bovifelis, S. heydorni, S. bovini and S. rommeli; other, unnamed species also infect cattle. Of these parasites of cattle, a complete life cycle description is known only for S. cruzi, the most pathogenic species in cattle. The life cycle of S. cruzi was completed experimentally in 1982, before related parasite species were structurally characterized, and before the advent of molecular diagnostics; to our knowledge, no archived frozen tissues from the cattle employed in the original descriptions remain for DNA characterization. Here, we isolated DNA from a paraffin-embedded kidney of a calf experimentally infected with S. cruzi in 1980; we then sequenced portions of 18S rRNA, 28S rRNA, COX1 and Acetyl CoA genes and verified that each shares 99­100% similarity to other available isolates attributed to S. cruzi from naturally infected cattle. We also reevaluated histological sections of tissues of calves experimentally infected with S. cruzi in the original description, exploiting improvements in photographic technology to render clearer morphological detail. Finally, we reviewed all available studies of the life cycle of S. cruzi, noting that S. cruzi was transmitted between bison (Bison bison) and cattle (Bos taurus) and that the strain of parasite derived from bison appeared more pathogenic than the cattle strain. Based on these newfound molecular, morphological and physiological data, we thereby redescribed S. cruzi and deposited reference material in the Smithsonian Museum for posterity.

Prevalence and first molecular identification of Sarcocystis species in feces of domestic dogs (Canis familiaris) in Egypt.

BACKGROUND: Sarcocystis species are obligatorily heteroxenous protozoan parasites with predator-prey life cycles. Global Knowledge about the epidemiology and the distribution pattern of different Sarcocystis species in dog feces are very scarce. Therefore, the current investigation was conducted to declare the occurrence of Sarcocystis in the fecal specimens of the most common canids in Egypt, the domestic dogs, and to identify the species present using various parasitological and molecular approaches. METHODS: A total of 100 dog fecal samples were collected and screened using fecal sugar flotation test for the presence of Sarcocystis oocysts/sporocysts. Additionally, thirty samples were used for genomic DNA extraction. The 18S rRNA gene fragment was the target of primers for a PCR, followed by purification and sequencing of the amplicons. RESULTS: Currently, the results obtained reviewed that 4% of fecal samples were positive for Sarcocystis spp. using LM. Additionally, Sarcocystis spp. were verified in sixteen dogs (53.3%, 16/30) using PCR and subsequent sequencing protocols. Statistically, insignificant difference in prevalence of sarcocystosis relative to age and gender was noticed. Morphologically, the detected sporocysts measured 13.2-16.0 × 9.4-11 µm. Based on the 18S rRNA gene, sequencing analysis of amplicons from sporocysts DNA revealed 99.82% nucleotide homology with published S. tenella partial nucleotide sequences from sheep in Iraq and Iran. CONCLUSIONS: This is the first molecular evidence in support of the final host role of domestic dogs in the life cycle of S. tenella in Egypt, which provides a precious diagnostic tool for further epidemiological studies and for the assessment of the effectiveness of control measures for this disease.

Recent insights into the morphology, molecular characterization and tissue localization of the caprine Sarcocystis species infecting domestic goats (Capra hiricus): Sarcocystis moulei, Sarcocystis capracanis, and Sarcocystis hircicanis.

Ninety-seven (64.67%) out of 150 domestic goats (Capra hiricus) carcasses were found to be infected by Sarcocystis moulei, Sarcocystis capracanis, and Sarcocystis hircicanis sarcocysts. Sarcocystis moulei macrosarcocysts were detected in the cardiac, esophageal, skeletal, lingual, and diaphragmatic muscles of seven goats (4.67%) out of the 150 examined animals, whereas the microscopic Sarcocystis species were found in (90/150 = 60%). Two morphotypes of S. moulei were observed. Morphotype (I) macrosarcocysts were large-sized oval, ovoid, spherical, and measured 2-7 mm in length x 2-6 mm in width. Sarcocystis moulei morphotype (II) macrosarcocysts were spindle-shaped, spheroid, sometimes elongated, and measured 1.8-6 x 0.5-2 mm. By TEM, all S. moulei morphotypes were ultrastructurally the same and had a sarcocyst wall that was characterized by highly branched or cauliflower-like villar protrusions (VP) with dumbbell-like structures. The VP interior was packed with well-developed microtubules in longitudinal and cross arrangements. Sarcocystis moulei cyst wall was 3-6 µm thick. Sarcocystis capracanis microsarcocysts detected herein had a cyst wall that ranged from 4-8 µm in thickness. The VP was upright finger-like or cylindrical. The PVM had electron-dense corrugations in the region of the VP. Few amounts of microfilaments were detected inside the cores of VP. Sarcocystis hircicanis had a thinner cyst wall (~1-3 µm) with hairy long VP that ranged from 1 to 7.5 µm in length. Microtubules were missing inside the cores of the VP. The three caprine Sarcocystis species were molecularly characterized on the level of the 18S rRNA, 28S rRNA, and Cox1 genes.

Detection of anti-Sarcocystis spp. antibodies in domestic cats, in southern Brazil.

Parasites of the genus Sarcocystis can infect several species of animals and cause multiple diseases such as equine protozoal myeloencephalitis. Felines are considered hosts of this protozoa; therefore, the present study aimed to detect anti-Sarcocystis spp.-specific antibodies in domestic cats that were under clinical evaluation, using the indirect immunofluorescence antibody test. Anti-Sarcocystis-specific immunoglobulin Gs were detected in 24 out of 497 (4.82%) cat serum samples. These findings support the fact that natural Sarcocystis infections do occur in cats. Furthermore, it highlights the importance of domestic cats as both intermediate and definitive hosts in the Sarcocystis life cycle, maintaining the parasite and serving as a source of infection for various other animals. To the best of our knowledge, this is the first study to identify antibodies against the genus Sarcocystis in cats from a region in southern Brazil.

Identification of Sarcocystis spp. in synanthropic (Muridae) and wild (Cricetidae) rodents from Argentina.

The occurrence of Sarcocystis species was investigated in synanthropic (Muridae) and wild (Cricetidae) rodents from Argentina. Nine species were captured (n = 356). Sarcocysts were detected in muscles of 8.7% (31/356) and 3.7% (4/106) of the rodents by histopathology and direct microscopic observation, respectively. PCR-sequencing targeting the 18S rRNA, cox1, and ITS1 regions was performed on samples with positive histopathology. Four different 18S rRNA sequences or sequence groups with high intra-group identities (99.6-100%) were detected in Mus musculus, Oxymycterus rufus, Akodon azarae, and Necromys lasiurus. Eight sequences showed 99.5-99.7% identity with S. dispersa. Thirteen sequences showed low identity (95.3-96.4%) with other Sarcocystis spp. The obtained coxI sequences (n = 9) were almost identical to each other and showed a high similarity with S. strixi (99.2-99.5%) and S. lutrae (99.1%), despite the 18S rRNA sequences from the same samples suggested the occurrence of at least two species. This suggests that coxI may not show high variability in Sarcocystis spp. that use rodents as intermediate hosts. Six ITS1 sequences were obtained, showing high identity but low coverage with several Sarcocystis spp. Multilocus sequence typing and BLAST analysis did not lead to an accurate species identification. Possible reasons are the detection of new species or the limited molecular information available from previously described Sarcocystis spp. Phylogeny suggests that the detected Sarcocystis spp. may use raptor birds or snakes as definitive hosts. This study represents the first molecular identification of Sarcocystis spp. in naturally infected rodents of the Cricetidae and Muridae families in South America.

Identification of Sarcocystis spp. in wild boars (Sus scrofa) from Argentina.

Sarcocystis spp. are intracellular protozoan parasites with an obligatory heteroxenous life cycle. The objective of this study is to identify Sarcocystis spp. in wild boar muscles from Argentina by light and transmission electron microscopy and molecular characterization. Muscle samples from diaphragm, tongue, masseter, intercostals, heart, and forelimbs of 240 wild boars were analyzed. Of the animals, 48.3% (116/240) were positive for sarcocysts by light microscopy, whereas 45.8% (110/240) were positive for Sarcocystis spp. by PCR targeting 18S rRNA fragment. These samples were subjected to a specific PCR for S. suihominis coxI gene, 3.6% (4/110) of which were weak positives. Unfortunately, sequence analysis was inconclusive. This could be related to a potentially low S. suihominis cyst load in the samples, or to an incomplete primer matching with the South American S. suihominis sequences. Seventeen individual sarcocysts were positive by PCR for the 18S rRNA fragment, whose sequences showed 99.75-100% identity with each other and with previously reported S. miescheriana sequences. A total of 21 cysts collected from 11 muscle samples and analyzed by TEM presented a cyst wall type compatible with S. miescheriana, and one cyst presented an ultrastructure compatible with S. suihominis. The latter came from a sample that also contained S. miescheriana cysts, indicating that the animal was co-infected. This is the first study that provides infection rates and describes and identifies morphological and molecular features of Sarcocystis spp. cysts in wild boars from South America.

The occurrence of Sarcocystis spp. in the myocardium of alpacas (Vicugna pacos) with associated risk factors in the Peruvian Andes.

Sarcocystis masoni n. sp. (known as "S. lamacanis") infects alpacas affecting their productivity and can cause a food poisoning syndrome in humans by consuming contaminated, undercooked cardiac muscle. There are few studies estimating the prevalence of this parasite in alpacas, although this information is crucial for the control and prevention of sarcocystosis. This study aimed to determine the frequency and density of Sarcocystis masoni n. sp. in the heart of alpacas in Huancavelica, a province of the Andean region of Peru. Heart samples were taken for histopathology from 104 alpacas slaughtered at the municipal slaughterhouse of Huancavelica, the official abattoir in the Huancavelica district. No macroscopic sarcocysts were observed. All alpacas (100%) had microscopic sarcocysts of Sarcocystis masoni n. sp., with no inflammatory reactions. The alpacas showed an average sarcocyst density of 60.8 ± 23.3/mm2. Sarcocysts density was significantly higher (p < 0.05) as the age of the animals increased. In addition, sarcocysts density was significantly higher (p < 0.05) in male animals aged 4 and 5 years compared to females of the same age. These results confirmed that heart sarcocystosis is highly endemic in Peruvian alpacas. Therefore, it is recommended that alpaca hearts be well-cooked at the time of consumption. The present study showed current data and contributes to the knowledge of this parasitosis. Studies of this nature are necessary because they are the basis for developing animal health programs.

Redescription, deposition of life-cycle stage specimens of Sarcocystis bovifelis Heydorn, Gestrich, Mehlhorn and Rommel, 1975, and amendment to Sarcocystis hirsuta Moulé, 1888.

There is considerable debate concerning the life cycles and taxonomy of Sarcocystis species in cattle. Of the 8 species of Sarcocystis named from cattle, 2 (Sarcocystis cruzi and Sarcocystis heydorni) are morphologically distinctive because their sarcocysts are microscopic and the sarcocyst wall is thin (<0.5 µm thick). The sarcocysts of the remaining species (Sarcocystis hirsuta, Sarcocystis hominis, Sarcocystis bovini, Sarcocystis bovifelis, Sarcocystis sinensis, Sarcocystis rommeli) have thick (5­8 µm) walls indistinguishable by light microscopy, alone. To provide needed clarity, I herein review the history, nomenclature and life cycle of S. bovifelis (originally named by Heydorn and associates from Germany), redescribe it and deposit specimens of its various life-cycle stages at a museum for future reference. I also provide means to distinguish this parasite from S. hirsuta. Cats are the definitive hosts for both S. bovifelis and S. hirsuta. The sarcocysts of S. bovifelis are microscopic, its sarcocyst wall is type 10g, it has 2 schizogonic stages in blood vessels and sarcocysts are formed between 25 and 30 days post-inoculation in striated muscles, but not in the heart. Sporulated oocysts are 17.1 × 12.7 µm and sporocysts are 12.8 × 8.4 µm. The sarcocysts of Sarcocystis hirsuta are macroscopic, up to 7 mm long, its wall is type 18. Nothing is known of the development of S. hirsuta in cattle tissues and in cat intestine. Size of its oocysts and sporocysts is uncertain.

Investigations on Sarcocystis species in the leg muscles of the bird family Corvidae in Lithuania.

Although three species of Sarcocystis, S. cornixi, S. corvusi and S. kutkienae, have been described in corvids, molecular studies of sarcocysts isolated from these birds are incomplete. Leg muscles of 83 corvids, 35 hooded crows (Corvus cornix), 21 western jackdaws (Coloeus monedula), 11 rooks (Corvus frugilegus), 9 common ravens (Corvus corax), 4 common magpies (Pica pica) and 3 Eurasian jays (Garrulus glandarius), from Lithuania were examined for the presence of Sarcocystis spp. in the present study. In methylene blue-stained squashed samples, sarcocysts were detected in 26 birds (31.0%). Under a light microscope, two morphological types of sarcocysts were distinguished (type A and type B). Sarcocysts of type A had a smooth and thin (about 1 µm) cyst wall, while cysts of type B were characterised by a thicker (1.4-2.5 µm) cyst wall. Based on ITS1 sequence comparison, sarcocysts of type A were identified as S. halieti and Sarcocystis sp. ex Corvus corax, whereas cysts of type B belonged to S. kutkienae and S. cornixi. Furthermore, it was demonstrated that a single bird could host two different Sarcocystis spp. Sarcocystis halieti was detected in corvids for the first time in the common raven and the hooded crow. Also, this study presents the first evidence of S. kutkienae in the hooded crow and the common magpie, and S. cornixi in the western jackdaw. Sarcocystis sp. ex Corvus corax was genetically characterised using almost complete 18S rDNA, partial 28S rDNA and complete ITS1 sequences. Sarcocystis sp. ex Corvus corax clustered together with S. columbae, S. corvusi and S. halieti in phylogenetic trees reconstructed using 28S rDNA and ITS1 sequences.

Morphological and molecular characterization of a Sarcocystis species infecting donkeys from China.

There is considerable confusion concerning the relationships among species of Sarcocystis found in donkeys and horses. Here, we describe a Sarcocystis species in Chinese donkeys (Equus asinus). Sarcocysts were found in 12 of 32 (37.5%) adult donkeys. By light microscopy, they were divided into two types, thin-walled and thick-walled. The thin-walled were macroscopic (up to 320 µm wide) and had short club-like protrusions (up to 2.7 µm long); the thick-walled were microscopic (up to 135 µm wide) and had villar protrusions (up to 5.4 µm long). Ultrastructures of the two types exhibited similar morphological characteristics, including bundled microtubules in the core of the villar protrusions penetrating diagonally into the ground substance, similar to wall type 11c. Three genetic markers, 18S rDNA, 28S rDNA, and mitochondrial cox1, obtained from the two morphotypes were sequenced and analyzed. The sequences of the three loci in the two morphotypes presented high intraspecific similarities of 97.2-99.5%, 97.8-99.6% and 99.0 - 99.9%, respectively. The most similar sequences in GenBank to the newly obtained 18S rDNA, 28S rDNA and cox1 sequences were those of Sarcocystis spp. in horses, with similarities of 90.0 - 97.5%, 94.7 - 95.1%, and 82.6 - 84.5%, respectively. Phylogenetic analysis using the three genetic markers indicated that the Sarcocystis sp. in donkeys formed an individual clade most closely related to a clade encompassing Sarcocystis spp. in horses. Further studies are needed for taxonomic identification of sarcocysts in donkeys because the Sarcocystis species in donkeys and horses are not successfully cross transmissible despite morphological similarities.

Distribution, prevalence, and intensity of Sarcocystis infections in sika deer (Cervus nippon) of free-ranging populations in Germany and Austria.

Sika deer (Cervus nippon), which are native to the Japanese islands and the adjacent mainland of eastern Asia, have been introduced into Europe and established free-ranging populations in several countries. Various Sarcocystis species have been identified recently from farmed "mainland sika" deer in Lithuania and native "Japanese sika" deer in Japan. To study the distribution, prevalence and intensity of Sarcocystis infection in free-ranging sika deer outside of their natural range heart and/or diaphragm samples of 311 animals from nine populations in Germany and Austria were examined by histology.Overall, sarcocysts were detected in either heart or diaphragm of 107/311 deer (34.4%) with prevalence ranging roughly from 5 to 50% among the populations. Considering the 263 animals with both heart and diaphragm available, prevalence varied significantly (p < 0.0001) among calves (20.2%), yearlings (40.3%), and adult deer (49.1%) but did not differ between male and female deer (48.3% vs. 43.7%; p = 0.6483). Occurrence of sarcocysts in heart vs. diaphragm indicated a marginal difference (27.8% vs. 20.9%; p = 0.0839). Intensity of infection in all but one heart positive and all diaphragm positive animals was low (< 10 sarcocysts per square centimeter muscle cut). While heart sarcocyst counts of yearlings and adult deer were higher than those of calves and were higher in male compared to female sika deer, diaphragm sarcocyst counts did not differ significantly between age groups and sexes. Sarcocystis infection was demonstrated at variable prevalence in sika deer in all populations but intensity is apparently low. Further studies are needed to identify the species of Sarcocystis infecting sika deer naturalized outside their natural range.

A novel RFLP method for identification of morphologically similar avian Sarcocystis species.

Protozoans of genus Sarcocystis are widespread parasites infecting mammals, birds, and reptiles. Morphology of their sarcocysts is an important criterion for species identification. However, as more and more morphologically similar Sarcocystis species are being found and described, additional methods for their routine diagnostics are needed. We investigated restriction fragment length polymorphism (RFLP) as potential alternative to sequencing data analysis for the identification of Sarcocystis species using birds as an intermediate host. The internal transcribed spacer 1 (ITS1) region sequences of seventeen Sarcocystis species (S. albifronsi, S. anasi, S. calchasi, S. columbae, S. cornixi, S. corvusi, S. cristata, S. halieti, S. falcatula, S. fulicae, S. kutkienae, S. lari, S. lindsayi, S. rileyi, S. turdusi, S.wenzeli, and S. wobeseri) of interest were analysed and five best-fitting endonucleases generating most informative restriction fragments were selected for routine testing. In general, RFLP analyses are always inconclusive as they target very short DNA sequences. However, it can be an irreplaceable technique when fast and cheap identification and discrimination of known species are required, which was our main goal and preliminary results indicate that RFLP could be successfully used when identifying closely related avian Sarcocystis species with just two nucleases.

Equine Protozoal Myeloencephalitis.

Advances in the understanding of equine protozoal myeloencephalitis (EPM) are reviewed. It is now apparent that EPM can be caused by either of 2 related protozoan parasites, Sarcocystis neurona and Neospora hughesi, although S neurona is the most common etiologic pathogen. Horses are commonly infected, but clinical disease occurs only infrequently; the factors influencing disease occurrence are not well understood. Epidemiologic studies have identified risk factors for the development of EPM, including the presence of opossums and prior stressful health-related events. Attempts to reproduce EPM experimentally have reliably induced antibody responses in challenged horses, but have not consistently produced neurologic disease. Diagnosis of EPM has improved by detecting intrathecal antibody production against the parasite. Sulfadiazine/pyrimethamine (ReBalance) and the triazine compounds diclazuril (Protazil) and ponazuril (Marquis) are effective anticoccidial drugs that are now available as FDA-approved treatments for EPM.