Macroscopic, histological, and molecular aspects of Sarcocystis spp. infection in tissues of cattle and sheep.

The macroscopic, histological, and molecular aspects of Sarcocystis spp. were examined in the tissues of two cattle and four sheep, 16 and eight fragments analyzed respectively, condemned in the slaughterhouse. All 24 samples were collected and analyzed for detecting macrocysts and macroscopic lesions. Subsequently, subdivided for direct examination, polymerase chain reaction and histopathological examination. All sheep tissues samples had grossly white round to oval tissue cysts, ranging from 0.3 to 1 cm in diameter. In contrast, cattle tissues did not present grossly visible cysts but had randomly distributed white-yellow foci with irregular contours. All samples from cattle and sheep had microscopic cysts. In the histological examination of sheep tissues, circular to elongated, encapsulated, basophilic structures ranging from 30 to 3,000 µm in length and 20 to 1,000 µm in width were observed within the skeletal muscle fibers. In cattle tissues, all cardiac muscle four fragments analyzed contained circular to elongated basophilic structures inside cardiomyocytes and in some Purkinje fibers. PCR were performed using the primers: 2L and 3H. In conclusion, all 24 tissues were infected with Sarcocystis spp., and S. gigantea (in sheep) and S. cruzi (in cattle). were the identified species by sequencing.

Contaminated water confirmed as source of infection by bioassay in an outbreak of toxoplasmosis in South Brazil.

The protozoan Toxoplasma gondii is a causative agent of toxoplasmosis, an important and widespread zoonotic disease. The transmission of this disease in humans includes ingestion of sporulated oocysts present in contaminated water or food. T. gondii oocysts are widely distributed and toxoplasmosis is considered a major food- and waterborne pathogen worldwide, making drinking water containing sporulated T. gondii oocysts a major source of contamination for people. In the first half of 2018, an unprecedented outbreak of toxoplasmosis was reported in the city of Santa Maria, southern Brazil. The temporal and spatial distribution of the cases strongly suggested a waterborne infection. Thus, the aim of this study was to investigate a possible involvement of treated water as a source of the outbreak. For this, piglets received potentially contaminated water ad libitum for 21 days and the infection was monitored by serology through IFAT and investigation of T. gondii DNA in tissues by PCR amplification of a 529 bp followed by mouse bioassays. All piglets receiving test water ad libitum for 21 days as well as positive controls seroconverted to T. gondii. T. gondii DNA was detected in 62.5% of the piglets that received test water. All mice inoculated with tissues from each positive piglet were PCR-positive. These results strongly indicated the presence of viable oocysts in the test water administered to the animals during the study.

Molecular Detection and Characterization of Sarcocystis Infection in Naturally Infected Buffaloes, Brazil.

ABSTRACT: Sarcocystosis is a disease caused by various Sarcocystis species, a coccidian protozoan parasite that infects humans and animals and is commonly found in ruminants. Although Sarcocystis occurs all over the world, the species responsible for infecting buffaloes in Brazil have not been identified. In this study, we used molecular methods to estimate the prevalence of natural Sarcocystis infection in buffaloes. Phylogenetic analyses were conducted for the first time to identify the species of this protozoan that are responsible for infecting buffalos in southern Brazil, Rio Grande do Sul state. Heart samples from 80 buffaloes were subjected to microscopic examination followed by molecular analysis. Microcysts were present in 19 (23.75%) of 80 samples. The genomic DNA from the 19 cyst samples was extracted and amplified, and six sequences were obtained. The analysis was performed with the StandenPackage software, and the nucleotide sequences generated were analyzed by comparison with sequences in GenBank. All the sequenced samples were identified as Sarcocystis levinei.

Natural Occurring Muscular Sarcocysts in Urban Domestic Cats (Felis catus) Without Sarcocystis-Associated Disease.

PURPOSE: Despite of classically acting as definitive hosts of different Sarcocystis species, domestic cats have been pointed out as possible intermediate hosts of S. neurona and S. felis. Nonetheless, details concerning natural sarcocyst development in cats without Sarcocystis-associated disease are scarce. This study aimed to characterize the natural occurrence of muscular sarcocysts in a random group of cats submitted for necropsy. METHODS: One hundred cats necropsied at a Veterinary Pathology Service were included. Nine different muscular tissues from each cat were sampled for histological analysis and Polymerase Chain Reaction (PCR) using multispecies primers for Sarcocystis neurona, Neospora caninum and Toxoplasma gondii. PCR-positive cases were sequenced for genus and species identification. Epidemiologic data was also analyzed. RESULTS: Tissue sarcocysts were identified in hematoxylin and eosin-stained slides from five cats, and S. neurona was the only confirmed species. Multifocal sarcocysts affecting two or more muscles were common among positive cats (4/5). Sarcocysts were identified within vastus lateralis (3/5), intercostal (3/5), subscapular (2/5) and diaphragm (2/5) sections. These cysts were always incidental necropsy findings. All sarcocyst-positive cats were from urban areas, among which two were feral and three were pets. Outdoor access was consistently reported. Two cats were positive for retrovirosis, and treatments with potentially immunosuppressive drugs were never stated. CONCLUSIONS: This study describes the natural occurrence of S. neurona muscular sarcocysts in a random group of cats without Sarcocystis-associated disease. These findings reinforce the participation of feral and pet cats from urban areas as natural intermediate hosts of S. neurona.

Anti-Sarcocystis Antibodies in Lambs Deprived of Colostrum.

INTRODUCTION: The objective of this study was to evaluate the presence of anti-Sarcocystis spp. specific IgG antibodies in serum samples from precolostral lambs to determine the occurrence of transplacental transmission of Sarcocystis spp. in sheep. METHODS: Blood samples were collected from 80 ewes and their respective lambs, immediately after lambing and before colostrum ingestion, respectively. The presence of anti-Sarcocystis spp. IgG was evaluated in serum samples using the indirect fluorescent antibody test (IFAT). Positive samples of the lambs were submitted to titration and IFAT to detect anti-T. gondii and anti-N. caninum specific IgG. RESULTS: Anti-Sarcocystis spp. IgG was detected in 62.5% of the ewes (50/80) and in 4% of the lambs of the seropositive ewes (2/50). None of the lambs from seronegative ewes were positive. The final titers of the positive lambs were 80. No cross reaction was detected among the positive samples to anti-Sarcocystis spp., anti-N. caninum, and anti-T. gondii IgG. The detection of anti-Sarcocystis spp. antibodies in serum samples of lambs deprived of colostrum suggests transplacental transmission of infection. Thus, the vertical transmission may be an alternative route of infection of Sarcocystis spp. also in sheep. Further studies are warranted to confirm transplacental transmission in sheep and to explain the importance of this infection pathway.