Survey of piroplasmids in wild mammals, unconventional pets, and ticks from Goiás state, midwestern Brazil

Abstract

Tick-borne piroplasmids are apicomplexan protozoa that infect a wide range of vertebrate hosts, with significant implications for animal and human health. This study investigated the occurrence and genetic diversity of piroplasmids in wild mammals, unconventional pets, and associated ticks in Goiás state, midwestern Brazil. Between April 2023 and January 2024, 105 blood samples, 22 tissue samples, and 300 ticks were collected from 21 mammalian species housed in wildlife screening centers, zoos, and veterinary clinics. Molecular screening targeting the 18S rRNA gene of piroplasmids detected a 25.7% (27/105) overall positivity, with gray brockets (Subulo gouazoubira) and South American tapirs (Tapirus terrestris) showing the highest infection rates. Three tick samples tested positive, including two Amblyomma sculptum nymphs and a male of Amblyomma dubitatum collected from a tapir and capybara (Hydrochoerus hydrochaeris). Cytauxzoon brasiliensis was reported, for the first time, in cougars (Puma concolor) from Goiás state, midwestern Brazil, indicating the role of this feline as a host of this parasite. Babesia goianiaensis was confirmed in a capybara, and Theileria terrestris in tapirs. Phylogenetic analyses clustered gray brockets-associated Theileria sequences with Theileria sp. previously detected in Neotropical deer from Brazil and Theileria cervi. While the phylogenetic analysis of amino acid sequences of the cytochrome c oxidase subunit III separated Theileria genotypes detected in S. gouazoubira from T. cervi, hsp70-based phylogenetic inferences clustered the genotypes detected in Tapirus terrestris with Theileria terrestris, suggesting host-specific evolutionary lineages. These findings contribute to the understanding of Piroplasmida diversity and circulation in South American wild mammals, emphasizing the need for enhanced molecular surveillance to elucidate transmission dynamics, assess potential health risks, and contribute to the establishment of wildlife conservation and One Health strategies.