First findings of Sarcocystis species in game deer and feral pigs in Australia.

Several wild game meat species, including deer and feral pigs are hunted and consumed in Australia. Feral pigs and deer are not indigenous to Australia, but they have proliferated extensively and established their presence in every state and territory. Following the report of a sambar deer displaying Sarcocystis like white cysts in its rump muscles, the present study was conducted to explore the prevalence of Sarcocystis infections in wild deer and feral pigs in the southeastern regions of Australia. Oesophagus, diaphragm, and heart tissue from 90 deer and eight feral pigs were examined visually for sarcocysts. All results were negative. PCR testing of randomly selected deer and feral pigs yielded positive results, which were subsequently supported by histopathology. This is the first study to report the presence of Sarcocystis spp. in deer and feral pigs in Australia. As no visual cysts were found on the heart or oesophagus that came back positive with PCR, infected animals, particularly those reared free-range, could be passing through meat quality checks unidentified. If people consume this meat without cooking it properly, it may lead to a human infection of Sarcocystis. However, a more targeted study focused on determining the parasite's prevalence and assessing its risks is necessary to determine if it constitutes a food safety issue. As this species has been found not only in feral pigs but also in domestic pigs, the potential for infection spreading between feral pigs and pigs in free-range livestock systems is high, potentially posing a large problem for the Australian pork industry, particularly with the increased emphasis on free-range pig husbandry. Future studies should concentrate on determining the species of Sarcocystis in feral animals commonly consumed as game meat to determine potential zoonotic risks. This could also include a more in-depth look at the prevalence of Sarcocystis infections in other game animals. Identifying where these parasites are present and to what extent, are important areas for future studies.

Disseminated Sarcocystis miescheriana infection in a finisher pig in Grenada.

Sarcocystis miescheriana infection is an important cause of carcass condemnation during meat inspection. The infection can cause morbidity and mortality in domestic pigs. In this study, an 8-month-old finisher pig was presented to a local abattoir for slaughter. Multiple white nodular lesions affecting the meat were observed, resulting in the condemnation of the carcass. Consequently, half of the carcass was submitted to the necropsy diagnostic laboratory in the School of Veterinary Medicine for further evaluation. Grossly, all superficial and deep muscle groups had severe multifocal macrocysts (3 mm × 2 mm × 1 mm) on the surface and extending deep into the skeletal musculature. Histopathology revealed moderate multifocal granulomatous and eosinophilic myositis with intralesional degenerated and intact parasites. Sample genomic DNA sequence analysis of the 18S RNA gene showed 100% identity to S. miescheriana in the GenBank. This is the first report of S. miescheriana in Grenada, West Indies.

Study of specific immunodominant antigens in different stages of Neospora caninum, Toxoplasma gondii, Sarcocystis spp. and Hammondia spp.

The family Sarcocystidae includes several intracellular coccidial parasites such as Toxoplasma gondii, Neospora caninum, Sarcocystis spp. and Hammondia spp. with heteroxenous life cycles involving different parasitic stages (oocysts/sporocysts, tachyzoites and bradyzoites in tissue cysts). The aim of this work was to evaluate monoclonal antibodies (MAb) (anti NcSAG1, anti NcSAG4 and anti TgCC2) and/or polyclonal antibodies (PAb) (anti NcSAG4 and anti TgBAG1) to label specific immunodominant antigens in different parasitic stages of N. caninum (oocyst, bradyzoite and tachyzoite), T. gondii (oocyst, cyst and tachyzoite), H. heydorni (oocyst), S. cruzi (cyst and bradyzoite) and S. falcatula (sporocyst). It was observed that the MAb directed against NcSAG1 reacted exclusively with N. caninum tachyzoites. In contrast, the MAb directed against NcSAG4 did not react with any of the parasites tested at any stage. The MAb directed against NcSAG4 reacted with both N. caninum and T. gondii tachyzoites, T. gondii tissue cysts and S. cruzi tissue cysts and bradyzoites. As expected, the MAb directed against the T. gondii tissue cyst wall antigen TgCC2 reacted with T. gondii tissue cysts, N. caninum bradyzoites, but also with T. gondii and H. heydorni oocysts and S. falcatula sporocysts. Finally, the PAb directed against the T. gondii bradyzoite proteinTgBAG1 reacted with T. gondii tissue cysts, N. caninum bradyzoites, and also with S. cruzi tissue cysts and bradyzoites. These data reveal a wide range of cross-reactions between different species of protozoa and between different developmental stages, which should be taken into account in the design and evaluation of diagnostic tests, as well as in the assessment of vaccination and challenge studies.

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.

Molecular identification of Sarcocystis species in wild boar (Sus scrofa) and pigs (Sus scrofa domesticus) in Brazil.

Sarcocystis spp. are protozoan parasites that form cysts in the organs and musculature of various animal species. The species Sarcocystis miescheriana and Sarcocystis suihominis are pathogenic to pigs and wild boars (Sus scrofa), acting as intermediate hosts, while humans are the definitive host for S. suihominis. To date, there have been no reports of the identification of these coccidian species in Sus scrofa in Brazil. Therefore, in this study, we conducted the first molecular identification of Sarcocystis species using PCR-RFLP and sequencing. A total of 210 samples were analyzed, of this total, 67 tested positive for Sarcocystis spp., representing 31.9% of the total samples assessed. Out of the total positive samples, 55 (82.1%) were identified as S. miescheriana and 8 (11.9%) as S. suihominis, a zoonotic species. Additionally, other species related to bovines, such as S. cruzi and zoonotic S. hominis, were detected in 3.0% of the samples, serving as contaminants in the pork products. The presence of S. suihominis in swine and wild boar samples is concerning due to the zoonotic risk and potential environmental contamination, as humans act as definitive hosts, also for the presence of S. hominis as a bovine contaminant in pork sausages. Furthermore, we confirmed the efficacy of the PCR-RFLP technique as a reliable tool for the identification of Sarcocystis species, demonstrating its potential use in laboratories for molecular diagnosis and rapid identification of these parasites, aiming to protect public health and ensure food safety.

A cyst-forming coccidian with large geographical range infecting forest and commensal rodents: Sarcocystis muricoelognathis sp. nov.

BACKGROUND: The geographic distribution and host-parasite interaction networks of Sarcocystis spp. in small mammals in eastern Asia remain incompletely known. METHODS: Experimental infections, morphological and molecular characterizations were used for discrimination of a new Sarcocystis species isolated from colubrid snakes and small mammals collected in Thailand, Borneo and China. RESULTS: We identified a new species, Sarcocystis muricoelognathis sp. nov., that features a relatively wide geographic distribution and infects both commensal and forest-inhabiting intermediate hosts. Sarcocystis sporocysts collected from rat snakes (Coelognathus radiatus, C. flavolineatus) in Thailand induced development of sarcocysts in experimental SD rats showing a type 10a cyst wall ultrastructure that was identical with those found in Rattus norvegicus from China and the forest rat Maxomys whiteheadi in Borneo. Its cystozoites had equal sizes in all intermediate hosts and locations, while sporocysts and cystozoites were distinct from other Sarcocystis species. Partial 28S rRNA sequences of S. muricoelognathis from M. whiteheadi were largely identical to those from R. norvegicus in China but distinct from newly sequenced Sarcocystis zuoi. The phylogeny of the nuclear 18S rRNA gene placed S. muricoelognathis within the so-called S. zuoi complex, including Sarcocystis attenuati, S. kani, S. scandentiborneensis and S. zuoi, while the latter clustered with the new species. However, the phylogeny of the ITS1-region confirmed the distinction between S. muricoelognathis and S. zuoi. Moreover, all three gene trees suggested that an isolate previously addressed as S. zuoi from Thailand (KU341120) is conspecific with S. muricoelognathis. Partial mitochondrial cox1 sequences of S. muricoelognathis were almost identical with those from other members of the group suggesting a shared, recent ancestry. Additionally, we isolated two partial 28S rRNA Sarcocystis sequences from Low's squirrel Sundasciurus lowii that clustered with those of S. scandentiborneensis from treeshews. CONCLUSIONS: Our results provide strong evidence of broad geographic distributions of rodent-associated Sarcocystis and host shifts between commensal and forest small mammal species, even if the known host associations remain likely only snapshots of the true associations.

First molecular identification and phylogenetic illustration of Sarcocystis species infection in Red Sea shortfin mako shark (Isurus oxyrinchus Rafinesque, 1810).

BACKGROUND: members of the genus Sarcocystis are intracellular obligate protozoan parasites classified within the phylum Apicomplexa and have an obligate heteroxenous life cycle involving two hosts. A more comprehensive understanding of the prevalence and geographic range of different Sarcocystis species in marine ecosystems is needed globally and nationally. Hence, the objective of this study was to document the incidence of Sarcocystis infection in sharks within the aquarium ecosystem of Egypt and to identify the species through the characterization of the SSU rDNA gene. METHODS: All organs of the mako shark specimen underwent macroscopic screening to detect the existence of a Sarcocystis cyst. Ten cysts were collected from the intestine and processed separately to extract the genomic DNA. The polymerase chain reaction (PCR) was accomplished by amplifying a specific 18S ribosomal RNA (rRNA) gene fragment. Subsequently, the resulting amplicons were subjected to purification and sequencing processes. RESULTS: Macroscopic examination of the mako shark intestinal wall sample revealed the presence of Sarcocystis cysts of various sizes and shapes, and sequencing of the amplicons from Sarcocystis DNA revealed a 100% nucleotide identity with the sequence of Sarcocystis tenella recorded from sheep in Iran; The mako shark sequence has been deposited in the GeneBank with the accession number OQ721979. This study presents the first scientific evidence demonstrating the presence of the Sarcocystis parasite in sharks, thereby documenting this specific marine species as a novel intermediate host in the Sarcocystis life cycle. CONCLUSIONS: This is the first identification of Sarcocystis infection in sharks, and we anticipate it will be an essential study for future screenings and establishing effective management measures for this disease in aquatic ecosystems.

Sympatric occurrence of Taenia saginata and Sarcocystis spp. in cattle from Narok County, Kenya: meat inspection findings with molecular validation.

The epidemiological picture of Taenia saginata infections in Kenya is fragmented with limited available data. Although Sarcocystis species are significant meat-borne parasites, few studies have explored their occurrence in Kenya. This study aimed to estimate the occurrence of bovine cysticercosis and screen for the presence of Sarcocystis spp. A meat inspection-based survey was conducted in ten abattoirs in Narok County, Kenya, and inspection for T. saginata cysticerci was limited to the Triceps brachii muscle. The apparent occurrence of the parasite was 5.4% (95% CI, 3.8, 7.6, n=573). Molecular confirmation of T. saginata was done via nested polymerase chain reaction targeting the mitochondrial 12S ribosomal RNA gene and restricted fragment length polymorphism. Sarcocystis species were identified using a multiplex polymerase chain reaction method targeting the 18S ribosomal RNA gene sequences and the mitochondrial cytochrome c oxidase subunit I gene. Of the 31 cystic lesions tested, 26/31 (83.9%) were confirmed to be T. saginata.Sarcocystis cruzi and S. hominis were detected in 8/31 (25.8%) and 1/31 (3.2%) of the cystic lesions, respectively. Co-infections of S. cruzi and T. saginata were found in 6/31 lesions (19.4%). The confirmation of bovine cysticercosis and S. hominis is suggestive of the presence of risky culinary and sanitation practices that facilitate transmission. This is the first report and molecular confirmation of Sarcocystis spp. in cattle in the country. The presence of both zoonotic S. hominis and pathogenic S. cruzi highlights an underexplored concern of veterinary and human health significance, warranting further epidemiological investigation.

Sarcocystis in horses from Rio Grande do Sul, Brazil: Molecular identification of Sarcocystis bertrami and Sarcocystis neurona in muscle tissues.

Horses are intermediate hosts of Sarcocystis spp. capable of forming cysts in their musculature. This study aimed to detect sarcocysts and investigate the presence of nucleic acids from Sarcocystis spp. in samples of striated muscles from horses in the State of Rio Grande do Sul, Brazil, necropsied at the Veterinary Pathology Laboratory of the Federal University of Santa Maria. A total of 108 samples were collected from 24 horses and examined through direct examination. Microscopic tissue cysts were observed in three samples: tongue (2) and esophagus (1) from two animals. Extractions were performed on the found cysts and tissues, even though sarcocystosis detection was not present. DNA samples were subjected to Nested-PCR using Tg18s primers, and the amplified products were subjected to Restriction Fragment Length Polymorphism (RFLP) using DdeI and HpaII enzymes. DNA belonging to Sarcocystis spp. was amplified in tissues from 91.7% (22/24) of the equines, and 67.6% (73/108) of the samples tested positive in the Nested-PCR reaction. The tissues with the highest detection frequency were: diaphragm 92.3% (12/13), gluteal muscle 77.2% (17/22), and esophagus 66.7% (4/6). In RFLP, Sarcocystis spp. was detected in 21 tissues from 11/22 equines, and cysts, identified through nucleotide sequencing, were determined to be S. bertrami. S. neurona was identified in 11 samples from 7/22 animals, with co-infection detected in 5/22 cases. The high detection rate indicates a concerning circulation of the protozoan, particularly the zoonotic S. bertrami found in all tissues, which are commonly exported for human consumption.

Morphological and molecular characterization of Sarcocystis spp. in pigs (Sus scrofa domestica) from Argentina.

Sarcocystis spp. are intracellular protozoan parasites with an obligatory heteroxenous life cycle. The objective of this study was to identify Sarcocystis spp. in pig muscles from Argentina, by light and transmission electron microscopy (TEM), and molecular studies. Muscles samples from 561 pigs (Sus scrofa domestica) were classified according to the breeding system in: intensive farming (IF, n = 295; animals kept in confinement during most of their productive cycle), or semi-extensive farming (SEF, n = 266; animals bred outdoors, generally family or backyard production). Results showed that 24.8% (139/561) were positive by light microscopy, with a significantly higher prevalence in the SEF (34.6%; 92/266) than the IF pigs (15.9%; 47/295) (p < 0.05). Of the 202 samples analyzed by PCR, 96 were positive (47.5%) for the 18S rRNA (18S ribosomal RNA) fragment. All samples analyzed by the S. suihominis specific coxI (mitochondrial cytochrome c oxidase subunit I) PCR (n = 235; 96 positives by 18S rRNA PCR and 139 positives by light microscopy) were negative. Fourteen individual cysts were positive for the 18S rRNA PCR and sequenced. Consensus sequences obtained from the 18S rRNA fragment PCR ranged from 613 to 880 bp and showed 100% of identity between them and with previously reported S. miescheriana sequences. In all the pig samples analyzed by TEM, cyst wall ultrastructure was compatible with S. miescheriana. This is the first study that provides infection rates and describes and identifies morphological and molecular features of Sarcocystis spp. cysts in pigs from Argentina.

Detection of Toxoplasma gondii and Sarcocystis sp. in the meat of common minke whale (Balaenoptera acutorostrata): A case of suspected food poisoning in Japan.

A case of suspected food poisoning related to the consumption of raw meat from a common minke whale (Balaenoptera acutorostrata) was reported in Tokyo, Japan, in June 2020. Microscopic analysis revealed tissue cysts of Toxoplasma gondii and sarcocysts of Sarcocystis sp. in whale meat. The SAG2 and ITS1 region sequences of T. gondii were detected in the DNA extracted from the meat. Genotyping of the multilocus nested PCR-RFLP using the genetic markers SAG1, SAG2 (5'- SAG2, 3'-SAG2, and alt. SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico revealed that the genotype of T. gondii was type II, with a type I pattern for the L358 locus. In the phylogenetic analyses of the six loci (GRA6, GRA7, SAG1, HP2, UPRT1, and UPRT7), these sequences clustered into haplogroup 2. Moreover, the sequences of the virulence-related genes ROP5 and ROP18 of T. gondii isolated from whale meat were similar to those of the type II ME49 reference strain. Sequence analyses of the mtDNA cox1 gene, 18S rRNA gene, and ITS1 region indicated the highest similarity of sarcocyst isolated from whale meat to Sarcocystis species that infect birds or carnivores as intermediate hosts; however, the species could not be identified. To our knowledge, this is the first report of T. gondii and Sarcocystis spp. being detected in same whale meat ingested by patients involved in a suspected food poisoning case in Japan.

SARCOCYSTIS AND OTHER PARASITES IN FECES OF BOBCATS (LYNX RUFUS) FROM MISSISSIPPI.

Rectal contents of 56 adult bobcats (Lynx rufus) in 2014 and 2017 from remote areas of Mississippi were examined microscopically for parasite stages after the sugar flotation method. Among the helminths, eggs/larvae found were: Paragonimus sp. in 12, Toxocara cati-like in 16, trichurid-capillarid-like in 3, hookworms in 27, and lungworms in 28. Among the protozoa, oocysts/cysts found were: Cystoisospora felis-like in 2, Cystoisospora rivolta-like in 4, Cryptosporidium sp. in 1, and Giardia sp. in 1. Additionally, numerous Sarcocystis sporocysts were detected in the feces of 12 bobcats; sporocysts were described morphologically. The status of C. felis derived from the bobcat and other wild felids is reviewed and compared with C. felis from the domestic cat. It is the first record of C. rivolta from the bobcat. The presence of eggs of Paragonimus sp. and T. cati in feces of 21.4% and 28.5%, respectively, suggests a role for the bobcat in the dissemination of these zoonotic helminths in the environment in the wild. Taxonomy of coccidia of wild Felidae is discussed and Isospora lyncisLevine and Ivens, 1981 from the Lynx is now regarded as a species inquirenda.

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.

Purification and characterization of cysteine protease of Sarcocystis fusiformis from infected Egyptian water buffaloes.

Sarcocystis spp. infects water buffaloes (Bubalus bubalis) causing sarcocystosis. In the present study, Sarcocystis fusiformis was recognized in Egyptian water buffaloes based on histological observation and molecular analysis of internal transcribed spacer 1 (ITS1), 18S ribosomal RNA (18S rRNA) and cytochrome c oxidase subunit I (COX-1) gene fragments. Chemotherapy and vaccines against Sarcocystis spp. could potentially target proteases because they may play a crucial role in the infection. Cysteine proteases are multifunctional enzymes involved in vital metabolic processes. However, the involvement of proteases in S. fusiform infection has not yet been characterized. Here, the purification and study on some biochemical properties of protease isolated from cysts of S. fusiform were carried out. Protease with a molecular weight of 100 kDa was purified. LC-MS/MS analyzed the protein sequence of purified protease and the data suggested that the enzyme might be related to the cysteine protease. The purified protease exhibited maximum activity at pH 6 and a temperature of 50 °C. The Michaelis-Menten constant (Km), the maximum velocity (Vmax), and the turnover number (Kcat) were determined. The complete inhibition effect of cysteine inhibitors indicated that the purified enzyme is a cysteine protease. The results suggested that S. fusiform proteolytic enzyme may be necessary for parasite survival in water buffaloes by digesting host tissues. Therefore, cysteine protease could be a suitable target for vaccinations.

Macroscopic sarcocystosis in a pig carcass from an Italian abattoir.

Different food-safety institutions, including the European Food Safety Authority, encourage monitoring and characterising Sarcocystis spp. in animals and foodstuffs; among meat-producing animals, domestic pigs (Sus scrofa domesticus) can host two different Sarcocystis spp., that is Sarcocystis miescheriana and the zoonotic Sarcocystis suihominis. Herein, we report for the first time the presence of macrocysts of Sarcocystis miescheriana in a domestic pig resulting in carcass condemnation. In North-West Italy, in June 2022 the carcass of a clinically healthy sow was condemned due to the detection of multifocal macroscopic whitish fusiform lesions. Affected muscle samples were submitted to histological and molecular analyses targeting the mtDNA cox1 and 18S rRNA genes. At gross examination and histology, well demarcated, oval or elongated macrocysts up to 8 mm in length characterized by a calcified central core surrounded by fibrosis were detected. The molecular amplification and sequencing of the cox1 mtDNA and 18S rRNA genes revealed the presence of Sarcocystis miescheriana DNA in all sampled macrocysts. Our study provides the first molecularly confirmed case of Sarcocystis miescheriana infection in a domestic pig in Italy. The present report highlights the need to increase data related to the occurrence and the prevalence of Sarcocystis spp. in meat-producing animals, and in wild and domestic pigs in particular, taking into account the zoonotic potential of Sarcocystis suihominis and the possible financial losses related to carcass discard due to macroscopic Sarcocystis spp. cysts.

Description of Sarcocystis platyrhynchosi n. sp. (Apicomplexa: Sarcocystidae) from domestic ducks Anas platyrhynchos (Anseriformes: Anatidae) in China.

BACKGROUND: Limited data are currently available on protozoan parasites of the genus Sarcocystis that infect their avian hosts within the order Anseriformes (waterfowl). To date, no Sarcocystis species has been recorded in ducks in China. METHODS: Leg muscles were sampled from 26 domestic ducks (Anas platyrhynchos) in China in 2021. Morphological characteristics of sarcocysts detected in the muscle tissue were described using light microscopy (LM) and transmission electron microscopy (TEM). Genomic DNA was extracted from single sarcocysts obtained from different ducks, and three genetic markers, 18S ribosomal DNA (18S rDNA), 28S ribosomal DNA (28S rDNA) and mitochondrial (mt) cytochrome oxidase subunit 1 (cox1), were amplified and cloned for sequence analyses. RESULTS: Sarcocysts were observed by LM in only three of the 28 samples (10.7%). These sarcocysts had a thick cyst wall with numerous brush-like villar protrusions (vps) of 3.8-4.3 µm in length (n = 30) on the cyst surface. TEM observation showed that the sarcocysts had lanceolated vps. Each vps narrowed in the stalk and contained a bundle of microtubules that extended into the ground substance. Comparisons of the new sequences with those deposited in GenBank showed that the most similar sequences were those of Sarcocystis halieti in the great cormorant Phalacrocorax carbo and European starling Sturnus vulgaris, and Sarcocystis calchasi in the domestic pigeon (Columba livia) at the 18S rDNA (99.1% identity); Sarcocystis wenzeli from the domestic chicken Gallus gallus at the 28S rDNA (95.9-96.0% identity); and Sarcocystis speeri from the opossum at the mtcox1 (98.2% identity). The new 18S rDNA, 28S rDNA and mitochondrial cox1 sequences shared up to 99.0%, 95.6% and 97.7% identity, respectively, with those of Sarcocystis spp. obtained from Anseriformes avian hosts. Phylogenetic analysis inferred from the sequences of the three genetic markers placed the organism within a group of Sarcocystis spp. obtained from avian or carnivorous intermediate hosts and avian, marsupial or carnivorous definitive hosts. Based on the morphological observation and molecular analyses, the organism found in the Chinese domestic ducks was regarded as a new species and named Sarcocystis platyrhynchosi n. sp. CONCLUSIONS: Based on morphology and sequence analyses, the microcysts diagnosed in the domestic ducks examined in this study were named as a new species. This is the first record of Sarcocystis spp. from waterfowl in China. Sarcocysts of similar morphology occur frequently in different Anseriformes birds, and the relationships among these species need to be further clarified in future studies using more molecular markers.

Natural infection with Toxoplasma gondii, Neospora caninum and Sarcocystis species in domestic pigeons (Columba livia domestica) in Iran.

Pigeons are common birds around the world and may act as intermediate hosts of the tissue cyst-forming apicomplexan parasites Toxoplasma gondii, Neospora caninum and Sacrocystis spp. This study aimed to provide an overview on the prevalence of and exposure to these parasites in Iranian domestic rock pigeon (Columba livia domestica) through molecular, serological and histopathological examination. Blood and tissue samples (i.e., brain, heart, gizzard, neck, thigh, and pectoral muscles) were taken from 100 pigeons. Sera were screened by agglutination tests for detection of anti- T. gondii and N. caninum antibodies, genomic DNA from tissue samples were assessed by respective species-specific PCRs, and histopathological examination of tissues was carried out. A seroprevalence of 45 % to anti-T. gondii and 35 % to anti-N. caninum IgG was recorded. PCR detected T. gondii DNA in 28 pigeons. Sacrocystis spp. was detected in one animal, but sequencing of the 28 S rRNA gene product did not reveal the identity of the species. Histopathology revealed myocarditis, myositis, and gliosis in the heart, skeletal muscles, and brain, respectively. No Sarcocystis tissue-cysts were detected, but T. gondii tissue cyst-like structures in the brain (i.e., 4 %) and heart (i.e., 3 %) were found by histology. Data reported herein demonstrate that pigeons from Iran are infected with tissue cyst-forming apicomplexans, particularly T. gondii. Since domestic pigeons are in close contact with human populations, and consumption of their meat and egg is popular in different societies, control strategies for minimizing the risk of infection in both pigeons and humans are suggested.

Sarcocyst Quantification and Viability: Freezing Treatment as an Alternative to Carcass Condemnation.

PURPOSE: The inspection of animal products is important for controlling parasitic zoonoses. Some processes that guarantee food safety to consumers such as carcass condemnation cause economic losses. This study aimed to detect Sarcocystis cysts in cattle hearts obtained from slaughterhouses and to evaluate sarcocyst viability after freezing treatment. METHODS: When myocardial tissues were minced and subjected to fresh examination, sarcocysts were observed in all analyzed tissues resulting in 21.73 cysts/g of tissue. Sarcocyst viability was verified after tissue freezing at 35 ± 2 °C and - 20 ± 2 °C for 0-12 h. After freezing, the tissues were minced, and sarcocysts were collected and stained with Tripan Blue. In addition, cysts were mechanically disrupted to check bradyzoite viability. RESULTS: Cysts and bradyzoites were unviable at - 35 °C for ≥ 3 h and - 20 °C for ≥ 8 h. CONCLUSION: These results suggest freezing treatment as an alternative to condemnation of cattle carcasses contaminated with Sarcocystis spp. Similar studies using freezing treatment with other animals infected by Sarcocystis must be conducted.

Bovine sarcocystosis: Sarcocystis species, diagnosis, prevalence, economic and public health considerations, and association of Sarcocystis species with eosinophilic myositis in cattle.

Infections by Sarcocystis in cattle are ubiquitous worldwide. There is considerable debate concerning the identity of Sarcocystis spp. in cattle. Proper diagnosis of Sarcocystis spp. is important to assess their economic and public health importance. Currently there are seven named species: Sarcocystis hirsuta, Sarcocystis cruzi, Sarcocystis hominis, Sarcocystis bovifelis, arcocystis heydorni, Sarcocystis bovini and Sarcocystis rommeli. Additionally, there are unnamed Sarcocystis spp. Two species, S. hominis and S. heydorni, are zoonotic. One out of seven species (S. hirsuta, contracted from cats) forms macroscopic cysts which can be visible during carcass inspection. Current molecular characterization is based on DNA extracted from sarcocysts from naturally infected cattle because DNA was not characterized from tissues of experimentally infected cattle or feces of experimentally infected definitive hosts. Sarcocystis cruzi (transmitted via canids) is recognized as the most pathogenic species and it causes abortion, low milk yield, poor body growth, and outbreaks of clinical sarcocystosis and death. Additionally, Sarcocystis infections have been linked to an inflammatory condition of striated muscles termed bovine eosinophilic myositis (BEM). Cattle affected by BEM appear clinically normal. Diagnosis of BEM at slaughter occurs when inspecting the carcass surface, or once the carcass has been divided into prime cuts or quarters. Sex and breed have no apparent influence on prevalence of BEM. The condition evidently occurs with equal frequency in steers, cows, and heifers. Virtually all striated muscles can be affected including skeletal muscles, the muscles of the eye, larynx, and the heart. In the USA, regulations require condemnation of BEM-affected parts, or (in severe cases) the entire carcass. These aesthetic considerations result in economic losses. Cattle experimentally infected with Sarcocystis did not have BEM at slaughter. Here, we review the status of Sarcocystis spp. and BEM in cattle including prevalence, lesions, epidemiology, and association of BEM with different species of Sarcocystis.

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.