Novel Genotypes of Nidicolous Ticks and Their Associated Microorganisms From Spain.

The knowledge of the distribution, richness and epidemiological importance of soft ticks of the genus is incomplete. In Spain, five species have been recorded, including three ornitophilic nidicolous ticks, but their associated microorganisms remain unknown. This study aimed to investigate ticks from bird nests and their microorganisms. Ticks were collected extensively from natural cavities and nest-boxes used by European rollers () and little owls () in Southeastern and Central Spain. Ticks were morphologically and genetically identified and corresponding DNA/RNA tick extracts were analyzed [individually ( = 150) or pooled ( = 43)] using specific PCR assays for bacteria (Anaplasmataceae, /, and spp.), viruses (Flaviviruses, Orthonairoviruses, and Phenuiviruses), and protozoa (/ spp.). Six genotypes were identified, of which only those of ( = 8) were identified to the species level. other genotypes were closely related to each other and to ( = 83) and ( = 33), respectively. These two species have not been previously reported from Western Europe. Two additional genotypes ( = 4) clustered with , previously reported in Spain. The remaining genotype ( = 22) showed low sequence identity with any species, being most similar to the African . The microbiological screening revealed infection with a rickettsial strain belonging to and Rickettsia vini group in 74.7% of ticks, mainly comprising ticks genetically related to and . Other tick endosymbionts belonging to and species were detected in ten, one and one tick pools, respectively. In addition, one genotype, closely related to avian species, was found in one tick pool. Lastly, Anaplasmataceae, , and viruses were not detected. In conclusion, five novel genotypes and their associated microorganisms with unproven pathogenicity are reported for Spain. The re-use of nests between and within years by different bird species appears to be ideal for the transmission of tick-borne microorganisms in cavity-nesting birds of semiarid areas. Further work should be performed to clarify the taxonomy and the potential role of soft ticks and their microorganisms in the epidemiology of zoonoses.