Evaluation of the immunofuorescent antibody technique to identify dogs exposure to Sarcocystis neurona in rural areas of the city of Ilhéus, Bahia
Keywords: EPM. Neurological Disease. IFAT. Cross- Reactivity. Serology.
Sarcocystis neurona is a coccidian parasite that is the major cause of equine protozoal myeloencephalitis. Infection by S. neurona and induction of neurologic disease in dogs have been reported in North America, where the dog is considered an aberrant or accidental host of the protozoa. The dog is also definitive host of Sarcocystis cruzi and other species. The aim of this study was to test dog sera from rural areas of the city of Ilhéus, Bahia, to S. neurona and to evaluate potential serologic cross-reactivity to Sarcocystis cruzi by the immunofluorescent antibody technique (IFAT). Sera from 365 dogs were tested to S. neurona using merozoites produced in cell culture, and to S. cruzi, employing bradyzoites extracted from bovine myocardium confrimed by PCR and sequencing. The results obtained were evaluated with the following data about the dogs: age, gender, breed, residence, contact with horses, stockyard and wild animals, inhabiting close to forest, hunting habits, neurological disease and anti-parasite treatment, in order to gather better epidemiological information. As results, the frequency of dogs exposed to S. neurona was 3.83% and to S. cruzi was 6.57%., being that four samples (1.09%) were simultaneously positive for both antigens. Statistical analysis did not indicate association of antibodies to S. neurona and any of the analyzed variables. In conclusion, sera from dogs were reactive to S. neurona and S. cruzi antigens in the studied region. Serologic cross-reactivity probably doesn’t occurs for the species S. neurona and S. cruzi in dogs, or the animals were exposed to infectivity forms from both parasites or to genetically-related Sarcocystis species.