Prevalence of Sarcocystis spp. in Argentinean cattle

Departamento de Epizootiología y Salud Pública, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, 60 y 118, 1900 La Plata, Argentina.
Veterinary Parasitology (Impact Factor: 2.46). 12/2010; 177(1-2):162-5. DOI: 10.1016/j.vetpar.2010.11.036
Source: PubMed


Sarcocystis cruzi, S. hirsuta and S. hominis are apicomplexan parasites that affect cattle worldwide with variable prevalence. The aim of the present study was to evaluate the prevalence of Sarcocystis spp. in Argentinean cattle comparing microscopic fresh examination and molecular methods. Blood, myocardium and loin samples were collected in five slaughterhouses from a total of 380 bovines. Origin of animals was representative of the major beef cattle production area of Argentina. Samples were analyzed by fresh microscopical examination, transmission electron microscopy (TEM), IFAT and PCR-RFLP. Thin walled sarcocysts corresponding with S. cruzi were found in 99.5% of heart samples. Sarcocysts were detected in 73.1% of loin samples; 71.5% had S. cruzi cysts and 23.1% had thick walled sarcocysts (S. hirsuta or S. hominis). TEM observation revealed the presence of characteristic S. hominis and S. hirsuta cyst walls in 7 and 1 loin samples respectively. Using IFAT, 379/380 animals had titers 25 or higher, showing a full agreement with fresh examination. Amplification products were detected in 35.5% (135/380) of loin samples; however Sarcocystis species could only be determined by RFLP in 29 samples. Agreement between fresh examination and PCR was low (Kappa value=0.262). This is the first report of S. hominis and S. hirsuta in Argentina. Further studies are needed to improve the sensitivity of molecular methods for species identification, especially for differentiation of S. cruzi and S. hirsuta from the zoonotic species S. hominis. The results of the present study and others focusing on sensitivity and specificity of Sarcocystis spp. diagnostic methods should contribute to improve food safety.

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    • "Sarcocystis spp. cystozoites were obtained from naturally infected bovine hearts and were purified according to a previously described procedure (Moré et al., 2011). Briefly, 100 g of minced myocardium were mixed with 400 ml of digestion solution (2.5% pepsin, 1% HCl) and were placed in a magnetic stirrer for 20 min at 37 • C. The suspension was filtered through 300, 150, and 53 m sieves into 50 ml centrifuge tubes and centrifuged at 500 × g for 5 min and it was centrifuged at 500 × g for 5 min. "
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    ABSTRACT: 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. 18-20kDa antigenic region and N. caninum 17-18kDa 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.
    Veterinary Parasitology 09/2015; DOI:10.1016/j.vetpar.2015.09.011 · 2.46 Impact Factor
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    • ") 82.4% in the cattle in Australia (Savini et al., 1992), 97.0% in sheep, 97.4% in goat and 97.8 % in cattle in Iraq (Latif et al., 1999), 96.9% in sheep and 90.0% in cattle in Mongolia (Fukoyo et al., 2002), 99.5% in cattle in Argentina (More et al., 2011) 100% in sheep and 94.7% in cattle in Iran (Hamidinejat et al., 2010; Dehaghi et al., 2013). The low prevalence of sarcocystosis in meat producing animals in Malaysia in comparison with other countries could be attributed to the low population of stray dogs. "

    Tropical biomedicine 01/2015; 32(3):1-9. · 0.85 Impact Factor
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    • "It is therefore highly likely that the animals were in contact with their natural environment and had ingested tissue of potential IHs of Sarcocystis spp. that got infected via food or water contaminated with sporocysts from the feces of python snakes. A predator–prey relationship is much more likely for free-living animals or farm-bred animals reared under extensive conditions (Dubey et al. 1989; McAllister et al. 1995; Moré et al. 2011). As the 'farmers' officially declared, to regulatory authorities, that they breed all rodents used as food for the snakes themselves, and based on the facility conditions, where a direct contact of the snakes with wild rodents can be excluded, it seems unlikely that the infected snakes had been legally bred. "
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    ABSTRACT: SUMMARY Sarcocystis spp. represent apicomplexan parasites. They usually have a heteroxenous life cycle. Around 200 species have been described, affecting a wide range of animals worldwide, including reptiles. In recent years, large numbers of reptiles have been imported into Europe as pets and, as a consequence, animal welfare and species protection issues emerged. A sample of pooled feces from four confiscated green pythons (Morelia viridis) containing Sarcocystis spp. sporocysts was investigated. These snakes were imported for the pet trade and declared as being captive-bred. Full length 18S rRNA genes were amplified, cloned into plasmids and sequenced. Two different Sarcocystis spp. sequences were identified and registered as Sarcocystis sp. from M. viridis in GenBank. Both showed a 95-97% sequence identity with the 18S rRNA gene of Sarcocystis singaporensis. Phylogenetic analysis positioned these sequences together with other Sarcocystis spp. from snakes and rodents as definitive and intermediate hosts (IH), respectively. Sequence data and also the results of clinical and parasitological examinations suggest that the snakes were definitive hosts for Sarcocystis spp. that circulate in wild IH. Thus, it seems unlikely that the infected snakes had been legally bred. Our research shows that information on the infection of snakes with Sarcocystis spp. may be used to assess compliance with regulations on the trade with wildlife species.
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