AUTHOR=Palomar Ana M. , Veiga Jesús , Portillo Aránzazu , Santibáñez Sonia , Václav Radovan , Santibáñez Paula , Oteo José A. , Valera Francisco 

TITLE=Novel Genotypes of Nidicolous Argas Ticks and Their Associated Microorganisms From Spain

JOURNAL=Frontiers in Veterinary Science

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.637837

DOI=10.3389/fvets.2021.637837

ISSN=2297-1769

ABSTRACT=<p>The knowledge of the distribution, richness and epidemiological importance of soft ticks of the genus <italic>Argas</italic> is incomplete. In Spain, five <italic>Argas</italic> 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 (<italic>Coracias garrulus</italic>) and little owls (<italic>Athene noctua</italic>) in Southeastern and Central Spain. Ticks were morphologically and genetically identified and corresponding DNA/RNA tick extracts were analyzed [individually (<italic>n</italic> = 150) or pooled (<italic>n</italic> = 43)] using specific PCR assays for bacteria (Anaplasmataceae, <italic>Bartonella, Borrelia, Coxiella</italic>/<italic>Rickettsiella</italic>, and <italic>Rickettsia</italic> spp.), viruses (Flaviviruses, Orthonairoviruses, and Phenuiviruses), and protozoa (<italic>Babesia</italic>/<italic>Theileria</italic> spp.). Six <italic>Argas</italic> genotypes were identified, of which only those of <italic>Argas reflexus</italic> (<italic>n</italic> = 8) were identified to the species level. <italic>Two</italic> other genotypes were closely related to each other and to <italic>Argas vulgaris</italic> (<italic>n</italic> = 83) and <italic>Argas polonicus</italic> (<italic>n</italic> = 33), respectively. These two species have not been previously reported from Western Europe. Two additional genotypes (<italic>n</italic> = 4) clustered with <italic>Argas persicus</italic>, previously reported in Spain. The remaining genotype (<italic>n</italic> = 22) showed low sequence identity with any <italic>Argas</italic> species, being most similar to the African <italic>Argas africolumbae</italic>. The microbiological screening revealed infection with a rickettsial strain belonging to <italic>Rickettsia fournieri</italic> and <italic>Candidatus</italic> Rickettsia vini group in 74.7% of ticks, mainly comprising ticks genetically related to <italic>A. vulgaris</italic> and <italic>A. polonicus</italic>. Other tick endosymbionts belonging to <italic>Coxiella, Francisella</italic> and <italic>Rickettsiella</italic> species were detected in ten, one and one tick pools, respectively. In addition, one <italic>Babesia</italic> genotype, closely related to avian <italic>Babesia</italic> species, was found in one tick pool. Lastly, Anaplasmataceae, <italic>Bartonella, Borrelia</italic>, and viruses were not detected. In conclusion, five novel <italic>Argas</italic> 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 <italic>Argas</italic> ticks and their microorganisms in the epidemiology of zoonoses.</p>