Molecular detection and phylogenetic analysis of canine tick-borne pathogens from Korea

Ticks transmit more pathogens than any other arthropod vector and are of paramount veterinary and zoonotic significance. Domestic dogs are an important reservoir of zoonotic agents, particularly because of their close contact with humans. Previous studies in Korea have examined canine tick-borne pathogens (CTBP) by ELISA and real-time PCR methods. However, phylogenetic information on CTBP in Korea is lacking. This study assessed the prevalence, risk factors, and co-infectivity of CTBP such as piroplasms, rickettsiae, Coxiella burnetii, hepatozoa, hemotropic mycoplasmas, and Borrelia spp., using PCR and phylogenetic analyses. Of the 510 dogs tested, three CTBP, including Anaplasma phagocytophilum 16S rRNA (13; 2.6 %), Hepatozoon canis 18S rRNA (2; 0.4 %), and Mycoplasma haemocanis 16S rRNA (1; 0.2 %) were detected. PCR adapted to amplify A. phagocytophilum msp2 and groEL genes generated amplicons thereof in two out of 13 positive dogs. One shelter dog was co-infected with A. phagocytophilum and M. haemocanis. However, Ehrlichia spp., Rickettsia spp., C. burnetii, Borrelia spp., Babesia spp., and Theileria spp. pathogens were not detected. To the best of our knowledge, this is the first study to undertake a phylogenetic analysis of H. canis and M. haemocanis in dogs reared in Korea. Although previous studies have improved our understanding of evolutionary behaviors and host-pathogen relations of CTBP, additional investigations are required to pin down vectors and reservoirs of CTBP in Korea. A surveillance system for arthropod vectors and CTBP in dogs should be established to monitor pathogen distribution and mitigate pathogen spread proactively, such as with ectoparasite medications in dogs.