Díaz Fernández, PabloArnal, Jose LuisRemesar Alonso, SusanaPérez-Creo, AnaVenzal, José ManuelVázquez López, María EstherPrieto Lago, AlbertoFernández Rodríguez, GonzaloLópez Sández, Ceferino ManuelPanadero Fontán, RosarioBenito, AlfredoDíez Baños, PabloMorrondo Pelayo, María Patrocinio2018-10-302018-10-302017-12-20Díaz, P., Arnal, J., Remesar, S., Pérez-Creo, A., Venzal, J., & Vázquez-López, M. et al. (2017). Molecular identification of Borrelia spirochetes in questing Ixodes ricinus from northwestern Spain. Parasites & Vectors, 10(1). doi: 10.1186/s13071-017-2574-x1756-3305http://hdl.handle.net/10347/17638Background: Ixodes ricinus, the predominant tick species in Europe, can transmit the causative agents of important human diseases such as Lyme borreliosis (LB), caused by Borrelia spirochetes. In northern Spain, LB is considered endemic; recently, a significant increase of the annual incidence of LB was reported in the northwestern (NW) region. Methods: In order to provide information on the prevalence of Borrelia spp., pooled and individually free-living I. ricinus from NW Spain were molecularly analyzed. Positive samples were characterized at the fla and Glpq genes and the rrfA-rrlB intergenic spacer region to identify Borrelia species/genospecies. Results: Borrelia burgdorferi (sensu lato) (s.l.) individual prevalence and MIR were significantly higher in adult females (32.3 and 16%) than in nymphs (18.8 and 6.2%) and adult males (15.6 and 8.4%). Five Borrelia genospecies belonging to the B. burgdorferi (s.l.) group were identified: B. garinii was predominant, followed by B. valaisiana, B. lusitaniae, B. afzelii and B. burgdorferi (sensu stricto) (s.s.). One species belonging to the tick-borne relapsing fever group (B. miyamotoi) was also found, showing low individual prevalence (1%), positive pool (0.7%) and MIR (0.1%) values. To our knowledge, this is the first citation of B. miyamotoi in free-living ticks from Spain. Conclusions: The significant prevalences of B. burgdorferi (s.l.) genospecies detected in questing ticks from NW Spain are similar to those detected in northern and central European countries and higher to those previously found in Spain. These results together with the high incidence of LB in humans and the high seroprevalence of B. burgdorferi (s.l.) in roe deer shown in other studies reveal that the northwest area is one of the most risky regions for acquiring LB in Spaineng© The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise statedAtribución 4.0 Internacionalhttp://creativecommons.org/licenses/by/4.0/Borrelia burgdorferi (s.l.)Borrelia miyamotoiIxodes ricinusNW Spainjournal article10.1186/s13071-017-2574-xopen access