Rhipicephalus (Boophilus) microplus: Rickettsiae infection in Brazil

The tick Rhipicephalus (Boophilus) microplus has been considered a major pest of cattle in tropical regions of the world, inducing significant economic impact on livestock activity. In Brazil, the scenarios of Spotted Fever (SF) epidemic cycles involve Amblyomma sculptum and Amblyomma aureolatum, transmitting Rickettsia rickettsii, as well as Amblyomma ovale, transmitting R. parkeri strain Atlantic Rainforest. However, other potentially pathogenic species of Rickettsia, as well as new species of ticks with vector potential, have been reported for Brazil. Thus, during SF focus investigation and environmental surveillance performed by Brazilian National Network of Environment Surveillance for Tick-borne Diseases between 2011 to 2017, ectoparasites were collected from vertebrate hosts and the environment in rural and urban areas of different Brazilian biomes. Here we analysed Rickettsiae infection in Rh. microplus and possible roles of this tick species in the maintenance and circulation of Rickettsia sp. in SF endemic areas. Cattle tick samples were naturally infected with R. rickettsii, R. parkeri, R. felis, R. tamurae, R. rhipicephali and R. bellii. The data in this study demonstrate that Rh. microplus acquires Rickettsia infection, including pathogenic species, and indicates this tick as suggested marker of Rickettsiae potential presence or circulation.