RESUMO
Sarcocystis neurona and Neospora spp. are protozoan parasites that induce neurological diseases in horses and other animal species. Opossums (Didelphis albiventris and Didelphis virginiana) are definitive hosts of S. neurona, which is the major cause of equine protozoal myeloencephalitis (EPM). Neospora caninum causes abortion in cattle and infects a wide range of animal species, while N. hughesi is known to induce neurologic disease in equids. The aims of this study were to investigate S. neurona and N. caninum in tissues from opossums in the northeastern Brazil, and to isolate Brazilian strains of Sarcocystis spp. from wild opossums for comparison with previously isolated strains. Carcasses of 39 opossums from Bahia state were available for molecular identification of Sarcocystis spp. and N. caninum in their tissues, and for sporocyst detection by intestinal scraping. In addition, Sarcocystis-like sporocysts from nine additional opossums, obtained in São Paulo state, were tested. Sarcocystis DNA was found in 16 (41%) of the 39 opossums' carcasses; N. caninum DNA was detected in tissues from three opossums. The sporocysts from the nine additional opossums from São Paulo state were tested by bioassay and induced infection in nine budgerigars, but in none of the gamma-interferon knockout mice. In vitro isolation was successful using tissues from all nine budgerigars. The isolated strains were maintained in CV-1 and Vero cells. Three of nine isolates presented contamination in cell culture and were discarded. Analysis of six isolates based on five loci showed that these parasites were genetically different from each other and also distinct from S. neurona, S. falcatula, S. lindsayi, and S. speeri. In conclusion, opossums in the studied regions were infected with N. caninum and Sarcocystis spp. and represent a potential source of infection to other animals. This is the first report of N. caninum infection in tissues from black-eared opossum (D. aurita or D. marsupialis) and white-eared opossum (D. albiventris). Brazilian opossums are probably infected by different Sarcocystis spp. distinct from S. neurona and S. falcatula, or present a high level of genetic recombination.
Assuntos
Coccidiose/veterinária , Didelphis/parasitologia , Neospora/isolamento & purificação , Sarcocystis/isolamento & purificação , Sarcocistose/veterinária , Animais , Bioensaio/veterinária , Brasil/epidemiologia , Coccidiose/epidemiologia , Coccidiose/parasitologia , Melopsittacus , Camundongos , Filogenia , Sarcocystis/genética , Sarcocistose/epidemiologia , Sarcocistose/parasitologiaRESUMO
Foram investigadas áreas de risco de leishmaniose visceral canina no município de Camaçari, Bahia. Um total de 278 cães distribuídos em 141 residências, pertencentes a 20 áreas de risco investigadas, foi examinado sorologicamente (ELISA). A soroprevalência geral foi 21,7 por cento (56/258) depois da exclusão dos 20 cães usados no início do estudo para delimitar a área. Os resultados respectivos das análises univariada e multivariada dos fatores relacionados à infecção do cão por Leishmania chagasi, a captura e distribuição do vetor na área e a metodologia usada para localizar os focos caninos são discutidos.(AU)
Risk areas of canine visceral leishmaniasis in the city of Camaçari, Bahia, Brazil, were investigated. A total of 278 dogs from 141 homes pertaining to 20 investigated risk areas was serologically screened (ELISA). The general seroprevalence was 21.7 percent (56/258) after exclusion of 20 dogs used at the beginning of the survey to limit the study area. The respective results of the univariated and multivariated analysis of factors related to infection of dogs by Leishmania chagasi, to vector distribu-tion pattern in the area and to the methodology used to localize the canine focuses are discussed.(AU)