Exposure of dogs and cats to Borrelia miyamotoi infected Ixodes ricinus ticks in urban areas of the city of Poznań, west-central Poland

Abstract Background Borrelia miyamotoi is an emerging human pathogen causing relapsing fever-like disease termed B. miyamotoi disease. The bacterium belongs to relapsing fever borreliae and similarly as spirochete species from the group of Borrelia burgdorferi sensu lato, is transmitted only by hard-bodied ticks within the Ixodes ricinuscomplex. Borrelia miyamotoi has not been so far shown to cause illness in dogs or cats, and is poorly documented in veterinary medicine. The aim of our study was to determine the B. miyamotoi infection prevalence in (i) host-seeking and (ii) engorged Ixodes sp. ticks collected from dogs and cats during their inspection in veterinary clinics of the city of Poznań, west-central Poland. Methods Host-seeking ticks were sampled in dog walking areas localized in urban forested recreational sites of the city. We screened 1059 host-seeking and 837 engorged I. ricinus ticks removed out of 680 tick infested animals (567 dogs and 113 cats). Moreover, 31 I. hexagonus ticks (one larva, 13 nymphs and 17 females) were collected from three cats and one larva and one nympf from two dogs and one dog was infested with a single Dermacentor reticulatus female. Borrelia species were identified by amplification and sequencing of the V4 hypervariable region of the 16S rRNA gene and the flaB gene fragments. Results DNA of B. miyamotoi was detected in 22 (2.1%) of the host-seeking ticks, in all developmental tick stages, and in all study areas. A similar infection prevalence (1.8%) was identified in the engorged I. ricinus ticks. Out of the infested animals, 2.2% were exposed to B. miyamotoi positive ticks. Out of the I. hexagonus ticks, three (9.1%) one female and two nymph , yielded DNA of B. miyamotoi. A single Dermacentor reticulatusfemale collected from a dog tested PCR-negative for the bacterium. Conclusions Our results demonstrate that the bacterium is well-established and broadly present in tick populations from different urban ecosystems of the city of Poznań. The lack of difference in mean infection prevalence between animal-derived and host-seeking I. ricinus ticks, suggests that systematic surveillance of pets, may be useful to evaluate the risk of acquiring Borrelia miyamotoi disease in urban areas. Additional studies are needed to further elucidate the role of domestic and wild carnivores in the epidemiology of B. miyamotoi which remains unknown.