Cytauxzoon brasiliensis sp. nov. (Apicomplexa: Theileriidae), a new species infecting a little-spotted-cat (Leopardus tigrinus) (Carnivora: Felidae) from Brazil.

Cytauxzoon spp. have been detected in Brazil infecting mainly asymptomatic domestic cats and wild felids. However, the supposed genetic similarity with the pathogenic Cytauxzoon felis is questionable because it is based on analysis of short sequences of the 18S rRNA gene. Herein, we describe a novel Cytauxzoon species infecting an asymptomatic little-spotted-cat (Leopardus tigrinus) based on morphological, histopathological, and molecular analyses. The animal was attended presenting a history of a run-over with multiple traumas. Although the little-spotted-cat was stabilized, he died a few days later. Ring-shaped merozoites within erythrocytes were found on blood smears and in the abdominal effusion. In addition, schizonts were observed in histiocytes in the liver. Phylogenetic analyses based on both near-complete 18S rRNA and cytb genes positioned the obtained sequences in a unique clade, albeit closely related to Cytauxzoon felis from the USA. Genetic divergences ranging from 0.004 and 0.067-0.068 were found between the near-complete 18S rRNA and cytb sequences of Cytauxzoon sp. detected in the little-spotted-cat and C. felis, respectively. This study evidenced the circulation of a novel Cytauxzoon species, herein named Cytauxzoon brasiliensis sp. nov., in an asymptomatic wild felid species from Brazil. Further studies are necessary to identify Cytauxzoon species from domestic and wild felids in the country.

Piroplasmid infection is not associated with clinicopathological and laboratory abnormalities in cats from Midwestern Brazil.

Feline piroplasmids include the genera Babesia spp., Cytauxzoon spp., and Theileria spp. In Brazil, there are few reports regarding these hemoprotozoans; however, clinicopathological and molecular data are scarce. This study aimed to characterize the clinical relevance of these parasites through hematological, biochemical, and molecular approaches. For this purpose, 166 cats from Brasilia, Federal District, Midwestern Brazil, were screened using a quantitative polymerase chain reaction (qPCR) for piroplasmids based on the LSU4 mitochondrial gene, which resulted in an overall prevalence of 36/166 (21.7%). Twelve of 166 samples (7.2%) were positive for C. felis, while 19/166 (11.4%) were positive for Babesia vogeli. No samples tested positive for Theileria spp. Babesia vogeli and Cytauxzoon spp. LSU4 sequences showed identities of 97-100% and 99.3%, respectively, to US isolates. The hematological and biochemical findings did not differ significantly between the cats that tested positive and negative for piroplasmids. Although the lack of abnormalities in clinical and laboratory parameters does not eliminate the possibility that these cats were sick and recovered, it may suggest that the Brazilian strain of Cytauxzoon spp. is not as pathogenic as that from the USA, despite the high molecular identity with North American isolates.