RESUMO
Despite the great diversity of coccidians, to our knowledge, no coccidian infections have been described in Oecomys spp. In this context, we examined Oecomys mamorae Thomas (Rodentia: Cricetidae) from the Brazilian Pantanal for infections with enteric coccidia. Nine individuals were sampled, and one was found to be infected. The oöcysts were recovered through centrifugal flotation in sugar solution. Using morphological and morphometric features, we described a new species of Cystoisospora Frenkel, 1977. Sporulated oöcysts were ovoidal 20.0-29.1 × 16.4-23.2 (26.7 × 21.2) µm and contained two sporocysts, 12.9-19.1 × 9.4-13.9 (16.4 × 12.4) µm, each with four banana-shaped sporozoites. Polar granule and oöcyst residuum were both absent. We documented the developmental forms in the small intestine and described the histopathological lesions in the enteric tract. Our results indicate that the prevalence of Cystoisospora mamorae n. sp. in O. mamorae is low, and tissue damage in the enteric tract is mild, even in the presence of coccidian developmental stages.
Assuntos
Arvicolinae/parasitologia , Sarcocystidae/classificação , Animais , Brasil , Oocistos/citologia , Sarcocystidae/citologia , Sarcocystidae/fisiologia , Especificidade da Espécie , Esporozoítos/citologiaRESUMO
Phylogenies within Toxoplasmatinae have been widely investigated with different molecular markers. Here, we studied molecular phylogenies of the Toxoplasmatinae subfamily based on apicoplast and mitochondrial genes. Partial sequences of apicoplast genes coding for caseinolytic protease (clpC) and beta subunit of RNA polymerase (rpoB), and mitochondrial gene coding for cytochrome B (cytB) were analyzed. Laboratory-adapted strains of the closely related parasites Sarcocystis falcatula and Sarcocystis neurona were investigated, along with Neospora caninum, Neospora hughesi, Toxoplasma gondii (strains RH, CTG and PTG), Besnoitia akodoni, Hammondia hammondiand two genetically divergent lineages of Hammondia heydorni. The molecular analysis based on organellar genes did not clearly differentiate between N. caninum and N. hughesi, but the two lineages of H. heydorni were confirmed. Slight differences between the strains of S. falcatula and S. neurona were encountered in all markers. In conclusion, congruent phylogenies were inferred from the three different genes and they might be used for screening undescribed sarcocystid parasites in order to ascertain their phylogenetic relationships with organisms of the family Sarcocystidae. The evolutionary studies based on organelar genes confirm that the genusHammondia is paraphyletic. The primers used for amplification of clpC and rpoB were able to amplify genetic sequences of organisms of the genus Sarcocystisand organisms of the subfamily Toxoplasmatinae as well.(AU)
A filogenia da subfamília Toxoplasmatinae tem sido amplamente investigada com diversos marcadores moleculares. Neste estudo, a filogenia molecular da subfamília Toxoplasmatinae foi analisada através de genes de apicoplasto e mitocondriais. Foram analisadas sequências parciais de genes de apicoplasto codificadores da protease caseinolítica (clpC), e da subunidade beta da RNA polimerase (rpoB) e de gene mitocondrial codificador de citocromo B (cytB). Foram investigadas cepas adaptadas em laboratório de Sarcocystis neurona eSarcocystis falcatula, parasitos estreitamente relacionados, além de Neospora caninum, Neospora hughesi, Toxoplasma gondii (cepas RH, CTG e PTG),Besnoitia akodoni, Hammondia hammondi e duas linhagens geneticamente divergentes de Hammondia heydorni. A análise molecular, baseada em genes de organelas, não diferenciou claramenteN. caninum de N. hughesi, porém foi possível confirmar as duas linhagens de H. heydorni. Foram encontradas pequenas diferenças entre as cepas adaptadas em laboratório deS. falcatula e S. neurona em todos os marcadores moleculares avaliados. Concluindo, filogenias congruentes foram reconstruídas com os três diferentes genes que podem ser úteis em triagem de parasitos sarcocistídeos não identificados, para identificar sua relação com organismos da família Sarcocystidae. Os estudos evolutivos com genes organelares confirmam que o gênero Hammondia é parafilético. Osprimers utilizados para amplificação declpC e rpoB foram capazes de amplificar sequências genéticas de organismos do gênero Sarcocystis e da subfamília Toxoplasmatinae.(AU)