Rickettsial Infection in Ticks from a National Park in the Cerrado Biome, Midwestern Brazil

This study was carried out from February 2020 to September 2021 in Parque Nacional das Emas (PNE), a national park located in the Cerrado biome, midwestern Brazil, as well as in surrounding rural properties. Serum and tick samples were collected from dogs, terrestrial small mammals, and humans. Ticks were also collected from the environment. Dogs were infested with adults, whereas small mammals were infested by immature stages of spp., , , and . Ticks collected from vegetation belonged to several species of the genus , including , , , , and . Two species were molecularly detected in ticks: in from the vegetation and a sp. (designated sp. strain PNE) in and collected from lowland tapirs ( ). Based on short A gene fragments, this rickettsial organism showed 99.7-100% to . Seroreactivity to antigens was detected in 21.9% of dogs, 15.4% of small mammals, and 23.5% of humans. The present study reveals the richness of ticks and demonstrates the circulation of rickettsial agents in one of the largest conservation units in the Cerrado biome in Brazil. To our knowledge, this is the first report of a rickettsial phylogenetically related to in Brazil.