Strain diversity of Rickettsia amblyommatis in ticks infesting birds in the North Huetar conservation area of Costa Rica

Although the presence of rickettsial agents in ticks infesting wild birds in Costa Rica has been recently reported, information on strain diversity is limited to selected rickettsial species. In order to mine deeper into rickettsial agents of ticks infesting Costa Rica wild birds a total of 399 birds from the North Huetar Conservation Area of Costa Rica were captured, and 134 immature ticks (76 larvae and 58 nymphs) were recovered from 61 birds. Ticks were tested for the presence of Rickettsia spp. by conventional PCR and sequencing of the gltA, ompA, ompB, 17 kDa, and groEL genes. Six (11.3%) Amblyomma longirostre and Amblyomma geayi ticks collected from passeriform birds, yielded amplicons of the expected size. Amplicons were sequenced, and BLAST results collectively showed that all sequences had 99-100% nucleotide identity with Rickettsia amblyommatis (formerly, 'Candidatus Rickettsia amblyommii'). Three different R. amblyommatis strains were identified. Four new tick species-host associations and the first detection of R. amblyommatis in A. geayi in Costa Rica are also reported.