Immature ticks on wild birds and the molecular detection of a novel Rickettsia strain in the Ibitipoca State Park, southeastern Brazil

Birds are recognized hosts of ticks, especially for the immature stages which may harbor various species and strains of Rickettsia. To explore landscapes inhabited by birds and their ticks would expand the knowledge on host-parasite relationships and the rickettsiae. The aim of this paper was to record the diversity of ticks collected on wild birds and assess the phylogenetic position of a novel Rickettsia strain detected in immature ticks. Birds were captured in the Ibitipoca State Park, located in the Minas Gerais state, southeastern Brazil, as part of a long-term research project on the ecology of ticks, birds and Rickettsia. We found three tick species parasitizing birds: Amblyomma aureolatum (63 larvae, 10 nymphs), Haemaphysalis leporispalustris (28 larvae, seven nymphs) and Amblyomma romarioi (27 larvae). Among these, A. aureolatum was the most abundant species including 54% (73/135) of the collected ticks. New tick-host records were: A. romarioi on Turdus amaurochalinus and H. leporispalustris on Thamnophilus caerulescens, Saltator similis and Zonotrichia capensis. Of the 82 ticks tested for Rickettsia spp. by PCR, two larvae (2.5%) of A. romarioi were infected with 'Candidatus Rickettsia paranaensis', a novel putative Rickettsia species closely related to Rickettsia africae, Rickettsia sibirica and Rickettsia parkeri, as corroborated by our phylogenetic analysis. Finally, we present a list of all records of immature stages of H. leporispalustris on passerine birds in Brazil.