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.

(Sarcocystidae: Apicomplexa) from slaughtered sheep in southwest Iran

Sarcocystis species are intracellular protozoan which mostly complete their life cycle in two hosts. The parasite has a significant economic, medical and veterinary impact in many regions of the world and considered as a significant health problem in Iran. However, most of infections are asymptomatic and mortality is extremely rare. The present study aimed to determine the molecular phylogeny of the Sarcocystis species isolated from sheep slaughtered in southwest Iran, using mitochondrial DNA sequences of 18 S rRNA gene. The DNA was extracted from sheep muscular tissue (n = 60), and partial sequence of 18 S rDNA was amplified and sequenced. Phylogenetic analysis revealed two monophyletic clades representing S. moulei (n = 3) and Sarcocystis spp. (n = 3). BI posterior probability and MP bootstrap values strongly supported the monophyly of these clades. In conclusion, phylogenetic analysis of Sarcocystis species using 18 S rRNA gene could be helpful in identifying the new species of the Sarcocystis.

Prevalence and molecular assessment of Sarcocystis infection in livestock in northeast Iran

Sarcocystis is an intracellular parasite of the apicomplexa phylum. More than one hundred species of Sarcocystis can infect wildlife and livestock animals. Samples of the liver, heart, muscle and diaphragm were collected from sheep, goats and cattle in Gonabad, northeast Iran and subjected to macroscopic, microscopic, tissue digestion, sequencing and phylogenetic analyses of 18S-rRNA region. Tissue sections stained with hematoxylin and eosin were also provided for surveying sarcocysts in the samples. Tissue digestion showed that all animal samples (100%) were infected with Sarcocystis bradyzoites. Phylogenetic analysis indicated that out of 50% of sheep genotypes belonged to S. tenella, and 20% to S. moulei and S. arieticanis. Moreover, three samples of macroscopic specimens of sheep were identified as S. gigantea, 100% of cattle isolates infected with S. cruzi, 80% of goat isolates belonged to S. capracanis and one macroscopic specimen of goat (20%) identified as S. moulei. Sarcocystis infection is highly prevalent in livestock in northeast Iran, where a variety of Sarcocystis species are unequivocally circulating in the region.

Sarcocystis infection in beef and industrial raw beef burgers from butcheries and retail stores: A molecular microscopic study

Sarcocystis is a genus of eucoccidian parasites, which globally infects humans and various animals. In addition to economic losses in livestock industries, the parasite is a zoonosis that infects humans through contaminated beef and pork with the parasite sarcocysts. Therefore, this study was carried out to assess Sarcocystis contamination in beef and industrial raw beef burger samples from butcheries and retail stores in Tehran, Iran. Overall, 180 samples of 90 beefs and 90 raw industrial beef burgers with at least 80% meat were randomly collected in Tehran, Iran. Samples were studied microscopically after peptic digestion. Furthermore, sample genomic DNAs were used in conventional polymerase chain reaction (PCR) to amplify approximately 900-bp fragments from 18S ribosomal DNA. Of 180 samples, 170 samples (94.4%) were microscopically and 161 samples (89.44%) were molecularly positive for Sarcocystis spp. Eucoccidial DNA fragments were detected in 161 samples (89.4%), including 78 (86.6%) beef and 83 (92.2%) beef burger samples. No significant differences were found between the beef and beef burger infestations by Sarcocystis bradyzoites using statistical analysis (P > 0.05). Statistically significant differences were seen between the sample type and the intensity of parasites in samples (P = 0.003). Furthermore, differences between the conventional PCR results (positive/negative) and the intensity of parasites in samples were statistically significant (P < 0.001). The considerable prevalence of Sarcocystis spp. in beef and beef burger samples reflects high transmission of the parasite in meat producing cattle, which is important due to food hygiene. Although the most prevalent bovine species, S. cruzi, is not a zoonosis, it is highly recommended to follow guidelines on the parasite transmission prevention due to the existence of S. hominis as a zoonotic bovine species.

and transmission routes in sheep from Humid Pampa, Argentina

The aim of this study was to describe the frequency of ovine specific antibodies to Toxoplasma gondii, Neospora caninum and Sarcocystis spp. and to estimate different transmission routes of these infections. One hundred and thirty Texel sheep and their 117 Texel lambs were included in the study. Serum samples were tested for antibodies to T. gondii, N. caninum and Sarcocystis spp. using IFAT. Toxoplasma gondii seroprevalence was 10.00% in sheep (IC95%: 4.80-15.20%), being higher in adult sheep (≥12 year) than in younger sheep (OR 1.30; 95% CI, 1.10-1.50). N. caninum and Sarcocystis spp. seroprevalences were 1.54% (IC95%: 0.00-5.70) and 72.09% (IC95%: 67.70-82.70), respectively, with no association between age and seropositivity in sheep (P>0.05). T. gondii seroprevalence in lambs was 4.27% (IC95%: 0.61-7.94). No association between T. gondii serological status in sheep and their lambs was detected (P = 0.07). Two T. gondii and Sarcocystis spp. seropositive lambs were euthanized and T. gondii and Sarcocystis spp. DNA was detected by PCR in their tissues. In conclusion, the increase of T. gondii seropositivity in relationship with sheep age and the lack of association between sheep-lamb serological status, suggest that horizontal infection is the main transmission route in this flock as reported before. Due to the low number of N. caninum-seropositive ewes no assumptions can be done about the impact of this parasite in this flock. According with previous reports, the main transmission route for Sarcocystis spp. in this species in the present study was horizontal.

Acute fulminant necrotizing myopathy in a dog caused by co-infection with ultrastructural Sarcocystis caninum and Sarcocystis svanai-like apicomplexan protozoa

Typically, carnivores are the definitive and herbivores the intermediate hosts for protozoan Sarcocystis spp. In the definitive host, the parasite has sexual multiplication in the intestine. Asexual phases occur in the musculature of different intermediate hosts. Although intestinal sarcocystosis is common in dogs, muscular symptomatic sarcocystosis is rarely reported. Here we report a fatal dual Sarcocystis spp. infection in a dog. The dog had acute onset of non-ambulatory tetraparesis. While neurological findings suggested a generalized neuromuscular disease with peripheral neuropathy concordant with the neurological deficits, the highly elevated muscle enzymes were more suggestive of a myopathy. Despite supportive therapy, the dog died three days after the onset of clinical signs. Necropsy revealed severe monophasic multifocal myodegeneration with severe pyogranulomatous inflammation. Histology revealed multiple sarcocysts in skeletal muscles and a smaller number in the heart. In light microscopy, both thin-walled and very thin-walled sarcocysts were found in skeletal muscles. Transmission electron microscopy confirmed the presence of two types of mature sarcocysts. Morphologically, cysts were indistinguishable from Sarcocystis caninum and Sarcocystis svanai, which were previously reported in a dog from USA. A region of the 18S rRNA gene sequence confirmed the presence of one species, S. arctica/caninum, without evidence for a dual infection. This is the first report of muscular sarcocystosis in a dog in Europe and, intriguingly, revealed morphologically similar species across the Atlantic.

Isolated from Sheep (Ovis aries) in Babol Area, Mazandaran Province, Northern Iran

BACKGROUND

To differentiate Sarcocystis macro-cyst-forming species in slaughtered sheep in Babol area, Mazandaran Province, sequence analysis of 18S rRNA gene was performed.

METHODS

Overall, 150 slaughtered sheep were examined macroscopically in slaughterhouse, Babol and intra-abdominal and diaphragm muscles tissues infected with macro-cyst of Sarcocystis spp. were collected in 2013. One macro-cyst was isolated from the infected muscles of each sheep. The partial 18S rRNA gene was amplified by PCR and sequenced afterward.

RESULTS

The rate of infection with macro-cyst producing Sarcocystis spp. was 33.3% (50 / 150). The partial 18S rRNA gene of Sarcocystis species was amplified at the expected PCR product size (∼1100 bp) from all 50 macroscopic cysts samples. From 30 sequences DNA samples, 20 samples (66.7%), six (20%) and four (13.3%) isolates were identified as S. gigantea, S. moulei and Sarcocystis spp., respectively. Eight and thirty-four variations in nucleotide position were seen in partial sequence of the18S rRNA gene of S. gigantea and S. moulei.

CONCLUSION

Sheep can be considered as an alternative intermediate host for S. moulei. Furthermore, multiple alignments showed some variations in the consensus sequences of the isolates obtained in the current study compared with previously published isolates. To understand better the genetic diversity among Sarcocystis species complete sequences of the18S rRNA gene or sequence analysis of other genetic loci would be beneficial.

specific antibodies cross-react with Besnoitia besnoiti and influence the serological diagnosis of bovine besnoitiosis

Bovine besnoitiosis control remains a challenge because the disease continues to spread and control relies solely on accurate diagnosis coupled to management measures. However, recent studies have reported that routinely used ELISAs may raise a high number of false-positive results. Herein, cross-reactions between Besnoitia besnoiti antigens and anti-Neospora caninum and/or anti-Sarcocystis spp.-specific antibodies were studied in an in house ELISA since N. caninum and Sarcocystis spp. are closely related parasites, and both infections are highly prevalent in cattle worldwide. The serum panel was composed of the following categories: sera from B. besnoiti-seronegative (n=75) and -seropositive cattle (n=66), B. besnoiti-based-ELISA false-positive reactors (n=96) together with N. caninum (n=36) and Sarcocystis spp. (n=42) -seropositive reference cattle sera. B. besnoiti tachyzoite based western blot (WB) results classified animals as seropositive or seronegative. Sera were analyzed for the detection of anti-N. caninum by WB and ELISA and anti-Sarcocystis spp.-specific antibodies by WB and IFAT. Those samples recognizing a Sarcocystis spp. 18-20 kDa antigenic region and N. caninum 17-18 kDa immunodominant antigen were considered to be Sarcocystis spp. and N. caninum seropositive, respectively. The category of B. besnoiti based-ELISA false-positive reactors showed the highest number of sera with specific anti-Sarcocystis spp. and anti-N. caninum antibodies (74%; 71/96), followed by the N. caninum-seropositive cattle category (52.8%; 19/36). In contrast, few B. besnoiti-seronegative and -seropositive cattle showed antibodies against Sarcocystis spp. and N. caninum (10.7%; 8/75 and 1.5%; 1/66), respectively). This study revealed that B. besnoiti false-positive ELISA results were associated not only with the presence of anti-N. caninum and anti-Sarcocystis spp. antibodies (χ(2): 78.36; p<0.0001; OR: 34.6; CI: 14-88) but also with high antibody levels against them using ELISA and IFAT tests, respectively (p<0.05; t-test). These results may explain why only some animals seropositive to Sarcocystis spp. and/or N. caninum are Besnoitia false-positive reactors. Therefore, sera meeting these requirements should be included in future validations of serological tests for bovine besnoitiosis.

infection in cattle of Tabriz city, Iran

Sarcocystis is one of the most prevalent protozoan parasites in the striated muscles of livestock slaughtered for food such as cattle, sheep and goat. Meat that is heavily infected may be condemned as unfit for human consumption. The aim of this study was to determine the prevalence of Sarcocystis spp. in slaughtered cattle in Tabriz, northwest of Iran. The prevalence of Sarcocystis spp. infection was investigated in 670 cattle, slaughtered from April 2013 to October 2013 in the Tabriz abattoir, Iran using naked eye examination for macroscopic Sarcocysts, and peptic digestion, muscle squash, squeezing methods for microscopic types. Muscles from oesophagus, tongue, heart, diaphragm and cervical and abdominal of 670 slaughtered cattle were examined for Sarcocystis spp. cysts. The prevalence of microscopic Sarcocystis spp. cysts in cattle was detected in 100 % and there was detected in macroscopic cyst 8.2 % in examined cattle. There were no significant differences among the infection rates of the different organs (P > 0.05). There were no significant differences among the infection rates of the different ages (P > 0.05). The prevalence of macroscopic infection in the oesophagus was higher than that of the other organs (P < 0.05). The infection rate was independent of sex (8.25 % in males and 8.13 % in females, P > 0.05). This suggests that meat should be cooked sufficiently, since a macroscopic inspection may not provide true results. Also, it has of great importance the farmers to be trained not to feed their dogs and cats with uncooked meat, and the abattoir remnants to be burned, in order to be effectively broken of infection cycle between the intermediate and the definitive hosts in Tabriz city, northwest of Iran.

in cattle (Bos taurus) and water buffaloes (Bubalus bubalis) in Iran by PCR-RFLP

Sarcocystis species are cyst-forming intracellular protozoan parasites. Cattle are mainly infected with Sarcocystis cruzi, Sarcocystis hominis and Sarcocystis hirsuta. Water buffaloes are intermediate hosts for Sarcocystis fusiformis, Sarcocystis levinei (S. cruzi-like species), Sarcocystis dubeyi, Sarcocystis sinensis (S. hominis-like species) and Sarcocystis buffalonis (S. hirsuta- like species). The aim of this study was Identification of Sarcocystis spp. in slaughtered cattle and water buffaloes in Ahvaz, Khuzestan province by PCR-restriction fragment length polymorphism. Meat inspection was done on 124 cattle and 147 water buffaloes. From each animal tissue samples (each 50 g) from heart, esophagus, diaphragm and intercostal muscle were collected during meat inspection. Samples examined with digestion method. Genomic DNA of 80 positive samples was extracted and their 18S rRNA gene was amplified. PCR products were digested by restricted enzymes (FokI, SspI and DraI). S. cruzi in cattle and S. fusiformis in water buffaloes were identified. Our study clarified that sarcocystosis in cattle in Ahvaz district may be results acute infection according to determined species, but in buffaloes as S. fusiformis was detected we may expect only economic loss follow up slaughterhouse inspection.