Utilizing attached hard ticks as pointers to the risk of infection byBabesiaandTheileriaspecies in sika deer (Cervus nippon yesoensis), in Japan

Ticks are hematophagous ectoparasites that have a significant impact on their animal hosts. Along with mosquitoes, they are the main arthropod vectors of disease agents in domestic animals, wildlife and humans. To investigate the occurrence and prevalence of piroplasmids in ticks, DNA was extracted from 519 hard ticks collected from 116 hunted Hokkaido sika deer (Cervus nippon yesoensis). The success of the DNA extraction was confirmed by touchdown PCR targeting the mitochondrial 16S rDNA gene of ticks. Touchdown PCR and reverse line blot (RLB) hybridization targeting the 18S rRNA gene were used to detect 14 piroplasm species. All hard ticks parasitizing Hokkaido sika deer were identified as belonging to the generaIxodesandHaemaphysalis. In total 163 samples (31.4%) were positive forBabesiaandTheileriaspp. among tick species according to RLB hybridization. Tick DNA hybridized to the oligonucleotide probes ofTheileriasp.Thrivae (27.0% of ticks; 140/519),Theileria capreoli(10.6%; 55/519),Babesia divergens-like (1.7%; 9/519),Babesiasp. (Bab-SD) (0.6%; 3/519),Babesia microtiU.S. (0.4%; 2/519), andB. microtiHobetsu (0.4%; 2/519). The partial sequencing and phylogenetic analyses of the 18S rRNA gene confirmed the RLB hybridization results. Further investigations are needed to reveal the epidemiology and respective vectors of these pathogens.