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: 2.55). 12/2010; 177(1-2):162-5. DOI: 10.1016/j.vetpar.2010.11.036
Source: PubMed

ABSTRACT 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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    • "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.
    Parasitology 12/2013; 141(05):1-6. DOI:10.1017/S0031182013001960 · 2.35 Impact Factor
    • "In agreement with many other reports around the world on the prevalence of Sarcocystis spp. in cattle, S. cruzi was detected in a large proportion of the samples from Argentina, indicating frequent contact and efficient transmission of the parasite between canids and cattle in Argentina (Böttner et al., 1987; Dubey et al., 1989; Fukuyo et al., 2002; Moré et al.,2008, 2011; Odening et al., 1995). On the other hand, S. hominis was detected only in 2 samples of 380, indicating that this parasite is significantly less often detected in our study than previously reported (Domenis et al., 2011; Dubey et al., 1989; Jehle et al., 2009; Moré et al., 2011; Vangeel et al., 2007). In many regions, further studies are necessary, especially performing sequencing, multiplex real time PCR and experimental infections in order to confirm that the reported S. hominis prevalences are truly attributable to this parasite and not to S. sinensis. "
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    ABSTRACT: Cattle are intermediate hosts of Sarcocystis cruzi, Sarcocystis hirsuta and Sarcocystis hominis which use canids, felids or primates as definitive hosts (DH), respectively, and in addition of Sarcocystis sinensis from which the DH is unknown. The aims of the present study were to develop and optimize a multiplex real time PCR for a sensitive and specific differentiation of Sarcocystis spp. affecting cattle and to estimate the prevalence of Sarcocystis spp. in Argentinean cattle. The 18S rRNA genes from individual sarcocysts were amplified and cloned to serve as controls. For the amplification of bovine Sarcocystis spp. a total of 3 primers were used in combination with specific individual probes. Each assay was evaluated and optimized individually and subsequently combined in a multiplex assay (BovSarcoMultiplex real time PCR). The analytical specificity of the multiplex assay was assessed using 5ng of DNA of heterologous Sarcocystis spp. and other apicomplexan parasites, and no positive reactions were observed other than for the species the PCR targeted. The analytical sensitivity ranged between 0.0125 and 0.125fg of plasmid DNA (equivalent to the DNA of 2-20 plasmid DNA copies) or resembling DNA of 0.1-0.3 bradyzoites. A total of 380 DNA loin samples from Argentina were tested and 313, 29, 14 and 2 were positive for S. cruzi, S. sinensis, S. hirsuta and S. hominis, respectively. S. sinensis was the most prevalent species among thick walled Sarcocystis spp. in Argentinean cattle. Mixed infections were detected in 8.9% of all samples. Diagnostic sensitivity and specificity for the BovSarcoMultiplex real time PCR relative to previous microscopic examination for thin and thick-walled cyst were 91.5% and 41.7%, 36.3% and 95.9% respectively. Improved DNA extraction methods may allow to further increase the specific and sensitive detection of Sarcocystis spp. in meat samples.
    Veterinary Parasitology 04/2013; 197(1-2). DOI:10.1016/j.vetpar.2013.04.024 · 2.55 Impact Factor
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    • "are simple and inexpensive. One can use naked eye examination , light microscopy or histology (hematoxylin eosin staining) (Jehle et al. 2009), however, there are some more sophisticated methods, such as: immunofluorescence antibody test (IFAT) (Moré et al. 2011), ELISA (Heckeroth and Tenter 1999), Western Blot (Abdul-Rahman et al. 2002). More sensitive serological tests, which could distinguish S. hominis from S. suihominis, have not yet been developed (Tenter et al. 1991). "
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    ABSTRACT: Protozoa of the genus Sarcocystis (phylum Apicomplexa, family Sarcocystidae) is one of the most common parasites affecting animals. Interspecies diagnostic of Sarcocystis genus was based on electron microscopy for many years. Because of absence of visible differences between species with reachable magnifications, light microscopy is useless. In many cases serological diagnostic method have lack of sensitivity. A variety of molecular methods have been developed and used to detect and identify Sarcocystis spp. and to assess the genetic diversity among this protozoan from different population/hosts. Nowadays, molecular diagnostic is the common, time/cost effective method used all over the world to interspecies differentiation.
    Polish journal of veterinary sciences 01/2012; 15(3):589-96. · 0.71 Impact Factor
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