Diagnosis of Sarcocystis spp. in pigs and wild boars from Argentina

HELMAN, E.; DELLARUPE, A.; MORÉ, G.

Bern

Encuentro; 6th International Meeting on Apicomplexan Parasites in Farm Animals (Apicowplexa 2022); 2022

Sarcocystis spp. are protozoans with heteroxeneous cycle, forming muscle cysts in their intermediatehosts (IH) and oocysts with sporocysts in their definitive hosts (DH). Sarcocystis miescheriana and S.suihominis have swine as IH and canids and hominids as DH, respectively. The objectives of this workwere to identify and differentiate Sarcocystis spp. in pigs and wild boars muscles by microscopic andmolecular methods. Muscles samples from 561 pigs and 240 wild boars were processed byhomogenization and direct microscopic examination. Pigs were classified according to the breedingsystem in: intensive farming ([IF, n=295], animals kept in confinement during most of their productivecycle), or semi-extensive farming ([SEF, n=266], animals bred outdoors, generally family or backyardproduction). The PBS homogenization was performed with a mixer using 5-10 g of muscles, centrifuged and further observed in an inverted microscope. Cysts from 10 pigs and 11 wild boars were collected for transmission electron microscopy (TEM). Aliquots from homogenates were stored in microtubes for DNA extraction and subsequent PCR for the Sarcocystis spp.18S rRNA gene fragment. All wild boars samples were analyzed by PCR and for pigs 202 samples (n=104-IF and n=98-SEF) were randomly selected. Samples resulting positive were further processed by a S. suihominis specific PCR, targeting the cytochrome c oxidase (coxI) gene. Regarding pigs samples, 24.8% (139/561) were positive by direct microscopy, with a significantly higher prevalence in the SEF (34.6%; 92/266) than the IF pigs (15.9%; 47/295) (p